The Healthy Home
In our view, a healthy home is ‘one that incorporates healthy design elements, non-toxic building materials, and proper construction techniques. It "breathes", emits no toxic gasses, and is resistant to mould and decay.
Here are our top tips when designing a healthy building.
- Choose a simple build system
- Use natural and non-toxic materials
- Make the best use of natural light
- Ensure adequate ventilation
- Ensure that all building elements are compatible
- Use a breathable vapour open system
- Make the structure do the work
- Take a whole-house approach to design
- Include the end user in the design and build process
The toxicity of construction materials in our homes is a serious issue homes do not have to contain potentially damaging materials.mitigating this should be considered right at the start at the design stage.
Without a doubt, it is the control of moisture and the ventilation of the building that sits at the root cause of most building decay. We also have a huge issue with applying healthy principles to the biggest issue of all refurbishing existing buildings. Often in these cases, the prophylactic principle should be applied, where some anticipation of problems such as damp penetration can be mitigated by choosing materials that can hold onto moisture and let it go later (drying out) or at least minimise or contain the problem. The issue with a more synthetic and hermetic approach is that such problems can often remain hidden deep within the building structure for a long time and on discovery lead to costly and extensive repairs.
To apply healthy principles to any building project you first need to appreciate that the standards by which most UK construction is governed (and built to) do not account for the ‘health’ of a building in all but the most basic ways. So don’t expect a building that meets Building Regulations to be healthy.
To describe an unhealthy home can be more effective at persuading us to adopt healthy principles. We will all recognise the description of an unhealthy building as one that fails to control the internal environment leading to partial, then increasing, early decay of the building fabric in turn leading to mould growth, rot and a failure of the element(s) to physically perform, the description would further include the use of toxic chemicals in materials and the resulting expulsion into the air of these toxins over time, and it would include the use of materials that contain allergens.
Now most of us will recognise (and probably have experienced) the symptoms of poor building health but it is surprising how many of the houses built today have this very low on the agenda of considerations. The consequences of damp and unhealthy buildings can mean the aggravation of conditions like asthma, in the UK this is a real problem where 1 in 6 people have asthma a massive increase since the stable base in the 1970s with almost 2000 deaths per annum and 75,000 hospital admissions the cost to the state runs into £billions; most of this is directly linked to dust mite faeces which in turn is directly linked to relative humidity in houses, (as you find in an unhealthy house) other moulds, bacteria and diseases present in the same conditions are also linked to asthma.
The main contributors to poor building health are the following
- Water ingress
- Failure to control internal moisture
- Poor build quality
- The use of toxic materials
- Poor ventilation
- Material degradation over time leading to performance failure (e.g. air leaks)
- Poor design
You can see that it is not only the absence of harmful environmental characteristics but also the presence of beneficial ones that define a healthy building. Designers should begin by avoiding harmful elements and attempt to incorporate supportive beneficial ones. This is why the inclusion of items such as natural light, ventilation and acoustic insulation is as important as layout and functionality in the whole house approach.
Real progress is only made when the builder and future occupants work closely with the building’s designer to ensure that all these issues are addressed within the context of how the building is intended to be used.
Thankfully a lot of the approach to building healthy homes is common sense and can be summarised in a few simple principles
- Choose simpler building systems they are more failsafe
- Manage moisture by creating a breathable shell to provide a means for managing and buffering variations in moisture
- Include natural materials in many applications these will outperform synthetic ones.
- Be involved at every stage
As highlighted by recent events the toxicity inherent in our building materials can be a lethal problem especially in the case of fire, one of the most important materials used in the construction of a building is insulation, but can your choice of insulation really affect your health?
A well-insulated house or office will protect your health, comfort and lifestyle but how many of us know and understand how to achieve this?
Ecomerchant and Steico UK have joined forces to launch a protection campaign. It aims to champion the benefits of using natural insulation products, see www.ecomerchant.co.uk/protexion where you will find the wheel (illustrated below) which has dynamic segments (links) e.g. health, fire and acoustic which click through to more information on each subject, you can also download wood fibre insulation certifications and find toxicology reports and environmental product declarations, this is the type of clear unambiguous information that allows us to make informed and better design choices.
How we select insulation needs to be about having a real choice and for specifiers to be equipped with the right knowledge to compare materials on a like-for-like basis.
To design a well-insulated building, you need to make informed decisions throughout all phases of a construction project to ensure your building performs as you envisage as mentioned above.
However, selecting the right insulation is about more than just reaching building regulation compliance or ‘keeping in the heat’. It’s about ensuring a building protects its occupants’ entire well-being and comfort in the following ways.
How well does insulation keep the heat out?
In the UK, thermal insulation to protect from the cold is essential, particularly given ever-increasing energy costs. However, as demand for usable square footage of buildings increases, basement and loft conversions are the routes many now take. However, these parts of a home or office, are the spaces most prone to extremes in temperature. They, therefore, need more thought – i.e. how do you keep a space warm in winter but, for a loft, how to keep it cool come summer.
Compared with synthetic insulation materials, wood fibre insulation has a much higher density. This higher density means that natural insulation makes for a better heat buffer as the high midday temperature will only reach the internal side and be lost at night when the temperature is already cooler outside.
How a building’s breathability is hurting our health
A breathable structure is one that allows the passage of moisture.
With 90 percent of all building construction problems associated with water in some way, breathability is essential in measuring a building’s performance and preventing the accumulation of harmful water within the building’s fabric. These are fundamental in reducing health risks from mould, mites that those suffering from respiratory illnesses such as asthma and chronic obstructive pulmonary disease (COPD) are particularly susceptible to.
For effective breathability, there are four essential components that need to be considered:
- a moisture pathway
- a driving force
- a sorptive fabric
- vapour control.
Natural fibre insulation is most effective as it suppresses potentially harmful water by binding and releasing moisture which helps regulate humidity levels as the moisture moves.
A well-designed building takes into consideration how a material performs throughout the building’s entire life cycle. This includes ease of installation. Steico’s wood fibre insulation is simple and easy to fit (either packed or friction-fitted), eliminating installer error, keeping construction programmes, tight and costs, low.
How sustainability will save you time and money
While all insulation is helping the environment by limiting energy being burnt for heat, natural fibre insulation materials are comparatively more robust. This means that when it comes to disposal, they can be composted – i.e. no specialist waste facilities or landfill. Throughout their lifecycle, they will additionally have a much lower, and often, negative carbon footprint.
More than just protecting your home from fire
All insulations will meet fire safety standards, but this is a minimum rating. The key differentiator between natural and synthetic is that natural insulations will prevent the spread of fire and if burnt, will not give off toxic fumes such as cyanide as polyisocyanurates (PIR) might. See article link below to Alliance for Sustainable Building Products (ASBP) Healthy Buildings or Toxic Buildings?
Will the house be standing in 100 years?
Condensation is one of the costliest risks to buildings causing huge maintenance repairs and structural damage. Natural materials are better able to absorb and release water whilst remaining dry meaning it is better able to protect from and buffer moisture thereby becoming a key part of healthy living.
Comfort for occupants
When selecting insulation for a building, there are implications for the health of the occupants, the structure of the building, its impact on the environment, its acoustic properties, durability and carbon footprint.
Cancelling out the noise for a peaceful night’s sleep
The higher density of natural insulations - such as wood fibre - makes them better at reducing noise. Sounds external to the building, such as traffic or music, as well as those from within the building, through walls and ceilings are attenuated better by wood fibre than synthetic equivalents. In providing better protection from acoustic pollutants, occupants often report a building as being more restful and relaxing thereby encouraging better mental health.
When a building is well-designed and well-built, occupants should be at their peak comfort. With the average person spending approximately 80% of their lives in enclosed rooms, an occupant’s well-being is imperative. Therefore, the products used to achieve this should cover all the issues affecting a building’s construction, its impact on both its occupants and nature.
ASBP Healthy Buildings Conference summary of key points, https://asbp.org.uk/asbp-news/healthy-buildings-or-toxic-buildings
Read the expert’s view on healthy buildings including Professor Stephen Holgate CBE, Clinical Professor of Immunopharmacology at the University of Southampton and co-author of The Royal College of Physicians ‘Every breath we take‘ report, who explains why poor quality air is a lethal problem that affects us all, Consultant, Clinical Psychologist at UCL, Dr Sarah Mackenzie Ross who looks at the rapid rise in new chemical entities in our day-to-day environments and the consequences on our health, CIBSE’s Head of Sustainability Development Julie Godefroy who questions the role of Building Regulations in delivering healthy buildings and Professor Anna Stec, fire toxicity expert from University of Central Lancashire who looks at the potential fatal effects when plastics in the home burn.
www.asbp.org.uk for more on sustainable building products
www.ecomerchant.co.uk/protexion to see how insulation can provide so much more than keeping the heat in
Ecomerchant explains why this matters
For 20 years we (Ecomerchant) have focussed on sourcing the best materials to build energy efficient, healthy, and sustainable buildings. We want to reduce environmental impact be it pollution, waste, embodied energy or toxic ingredients in everything we do, its part of our DNA.
We haven’t been around this long by accident, natural materials such as wood are as old as building itself, proven over centuries, renewable and robust many natural products are popular because they are proven to work. Some of the most modern low energy buildings are made from natural materials, these aren’t mud huts but cutting-edge contemporary designs fit for our modern age. The processes used turn natural raw materials into performance products like insulation are some of the most sophisticated technologies in construction today.
Building technology doesn’t need to find chemically engineered, synthetic solutions to most building problems, most of them are solved in simpler more practical ways by adapting the inherent features of naturally occurring raw materials.
Human beings and trees were not born in space, and are not designed to live in alien surroundings. The materials which are the most natural and most ancient in our buildings are the materials which we have evolved with and which are the best for us and for construction. Nature works by building up and breaking down; these natural cycles, sometimes over millennia, include robust and long lasting materials like wood but nature eventually welcomes them back by providing a mechanism for them to be recycled back into the system without causing adverse impacts on the wider environment. In short, all natural products are a food of some description. The same is not true of man-made synthetic materials like plastic or petrochemical-derived products. Nature has not had time to develop a coping mechanism so they persist often with alarming consequences. These materials require their own closed-loop recycling system, the problem is that we haven’t created that either so they inevitably escape into the natural cycle where they cause harm.
We are most comfortable in buildings that don’t adversely affect the environment (this also includes the consequences of production and disposal of the materials used) or our health and we can all measure a reduction in the need for fossil-based fuels through our energy bills.
The UK home insulation market alone is huge worth over £800 million of this a staggeringly small amount is made up of natural insulation products– probably less than 1%. The rest is largely manmade and so sits outside the natural cycle of re-absorption and re-purposing by nature.
Accurate figures are hard to come by but there is one common factor we observe, natural insulation products are growing their market share. Insulation is an eponymous term as it is by definition an insulator, typically viewed in this country as a protector against cold.
As public understanding of environmental concerns has re-orientated how products are sold and marketed we have seen moves by manufacturers of synthetic insulation materials to ‘shoehorn’ in green claims about what their products contain and this has made people wonder what was in there before that was so bad for us.
All insulation products, no matter what they are made from, reduce greenhouse gas emissions by reducing demand for heat (or cold) so all have a form of inherent 'eco' credentials, but as this applies to all insulation the principle difference between types of insulation boil down to suitability for the intended application, stated efficiency in terms of capacity, embodied energy and toxicity, and this is what has made manufacturers re-align their marketing to reflect these concerns into a new way of re-describing existing products.
When choosing insulation its worth remembering that there is a significant difference between being 'designed' and being 'compliant', within UK domestic construction there is a tendency to focus on the latter especially when it comes to the building shell, this leads to a 'lowest common denominator' effect, a subject on which we have written about many times. A tendency to deliver only compliance can exclude beneficial features and expose us to unwelcome consequential problems. This also assumes that the level of compliance achieved will deliver the required performance and levels of comfort, which it can fail to do, for example, we have all experienced over hot 'rooms in the roof', compliant yes, but comfortable no, an overhot room can be unusable. Designing and specifying materials should take into account all possible features and benefits not simply compliance, this also helps mitigate cost differences as you only end up paying for delivered performance.
Insulation is capable of offering 10 key features – all of which are valuable in terms of building performance, installation and occupant comfort. perhaps you should be asking how many of these things your insulation can do.
- Insulates against cold or heat – these are the thermal benefits needed to create a comfortable internal environment and reduce energy bills
- Reduces sound – has acoustic properties – this helps create a better living environment. Some products are better than others.
- Buffers moisture – helps protect against structural damage, mould, fungal growth etc. This is a key part of healthy living, plus it protects your most expensive asset against repair and maintenance costs and keeping its value
- Reduces heat transfer by its mass (how much of it there is) especially true for ‘room in the roof’ and timber frame or lightweight construction, stopping excessive heat transfer requires more stuff in the insulation something that is inherent in all wood fibre products.
- Is simple and easy to fit – better fit equals less air movement equals higher efficiency. Badly fitted insulation doesn’t work, really badly fitted insulation is near useless, in other words badly fitted insulation is not insulation it’s just ‘stuff in a building’
- Fire: - almost all insulation has a similar fire rating, the key difference is that natural insulation is better at resisting the spread of fire than many synthetic options it also does not give off toxic fumes when burnt.
- Does not pollute or have the potential to pollute – no off-gassing- no toxic emissions – no concerns for asthmatics, or sensitised people and no health issues for installers
- No waste issues; can be recycled or reused without specialist mechanisms which carry a cost.
- Works at the same level over many years – doesn’t crumble, collapse, degrade or deteriorate and so lose its performance we have all encountered insulation that has failed in lofts walls and floors when we renovate or buy a property that needs updating, natural insulation is long lasting and doesn’t degrade.
- Meet or exceed the requirements of the Building Regulations. Remember Building Regulations are a minimum standard and do not require many of the above benefits to be met, except U value as a measure of conductivity – point 1. - be careful you don’t just choose an insulation that passes Regs, pick one that meets your needs, after all, they ALL have to meet the minimum standard so anything else is a bonus!
- Bonus Point. Choosing natural insulation can often eliminate the use of other materials such as membranes or boards so saving money and simplifying construction, after all, why take two products on to a building site when you can take one.
Most natural insulation will deliver all the above.
It’s a short step from this list to consider a genuinely natural product as long as it does the same job and is more or less the same price as a synthetic option. Never forget that bad insulation (insulation that is not fit-for-purpose usually cheaper, entry-level products made to a price) or badly chosen insulation is ‘not insulation at all’ if it doesn’t work reliably over many years it's just a waste of money.
Our customers have shown us that they ‘get it’ they know that natural insulation can do everything a synthetic one can do but with more benefits and fewer unwelcome associated issues such as waste, embodied energy or giving off toxic fumes when burnt.
This change in the market explains why natural insulation is being specified and used more and more in areas previously the sole domain of the big insulation manufacturers, it works, this is a trend that we only see increasing.
Most of the market growth is driven by customers wanting healthier products that function on a number of levels and compliment the higher performance being designed into modern buildings.
Terms such as breathable and airtight have created awareness that natural products have multiple and consequential benefits plus they do not degrade or pollute the environment. Our modern-day focus on well-being and health have caused many to question the provenance of materials they have to live with, manufacturers claims are under scrutiny and viewed less plausibly than before and the consequential effects on our environment made by our choices now form a key part of the decision making process.
It appears that the time for natural insulation materials is now and rather ironically the main driver is not the fact that they are natural it is often a performance and health-driven choice reinforced by the additional benefits they bring.
How we help you
Every home and every installation will be different but the methodology for calculating how much insulation is required, how it will perform and what type you need is a well-trodden path for our experts.
If you are unsure or need a hand figuring out what you want, just call us and ask for help. This is what we do day in day out. Our manufacturer partners and our team will always be able to help you to work out what is the best available option for your particular job.
If you know what you need then why not buy online you can shop when you want, all our products are delivered directly to you from stock.
Our commitment to you is to only sell natural insulation products.
How we can save you money. We are the only supplier of Steico insulation products to sell by the individual board or pack meaning we can keep unnecessary waste to a minimum. All our Steico products are priced individually by the board or pack (for Flex), buying online couldn’t be easier, just one click and the goods are on their way, just when you need them and no need to waste or store any surplus.
If you need help please call and ask, we are here to help just call 01793 847 444 or email firstname.lastname@example.org and we will do the work for you.
Wood fibre boards - product links
Download our installation guide
The answer to the question is 'because that's what the regulations allow and as many people regard the building regulations as a target standard that's what most people do.'
Current building regulations stipulate a minimum air leakage rate to be no more than 10m3/hr/m2, in the example below you can see that by comparison to Passive standard this equates to leaving an open hole in the building fabric equivalent in size to a typical a cash machine, whereas the Passive standard this hole size would be reduced to the size of a credit card.
Obviously, people do not leave a single gaping hole but the equivalent size will be distributed over the whole building which means that the energy efficiency is stripped away by the movement of air through the building fabric especially the insulation. This is why airtightness matters and sits at the core of improved energy efficiency.
What is Airtightness?
Often we are asked what the term airtightness means. Airtightness primarily focuses on the elimination of all unintended gaps and cracks on the external envelope of the building. Airtightness is an essential part of creating a healthy, comfortable, energy-efficient living environment. In contrast, air leakage is where leaks occur due to gaps and cracks that should not be there in the first place. This can account for up to 50% of all heat losses through the external envelope of a building. There are many factors which can cause air leakage such as poor build design, poor workmanship, or indeed the inappropriate use of materials. It is important to remember that an airtight building does not mean it is hermetically sealed, rather it means that the air leakage has been reduced to a minimum.
What role does ventilation play in airtightness?
Ventilation is crucial in all buildings, not just airtight ones. It is key to construct buildings which are both airtight and gap-free and then introduce a designed and controlled ventilation system which ensures that adequate fresh air is supplied to meet the needs of the occupants.
Can I not just add more Insulation?
Insulation requires high levels of airtightness to perform. This can be explained by the "woolly jumper" effect. Imagine going hill walking and you only wear a single layer then the wind blows through the woolly jumper quite easily. However, if you apply a light windshield over the single layer it has a dramatic impact as it reduces air movement through the jumper and consequently, the woolly jumper insulates much better
Therefore, for insulation in a building to perform it needs to be protected against air movement on both sides
1 - on the outside protecting against wind by using a windtight external membrane
2 - On the inside protecting against the hot air penetrating through it creating air movement through the insulation by using an airtight membrane
Short Video - Intelligent Airtightness Explained
What are the benefits of airtightness?
- Reduced heating costs
- Improved health - substances which can provoke allergies can be carried into a building via air leakage - air coming from outside in or from within the building fabric itself
- Improved building durability - Airtightness protects the building fabric against damage due to moisture-laden air leaking into the building envelope and condensing
- Reduced callbacks - Airtightness focuses on build quality and quality workmanship
- Improved comfort levels - Airtightness is a key component in reducing overheating in summer and insulating better in winter
- Improved Acoustics - Air is a very effective medium for transporting sound. Higher levels of airtightness means more effective reduction of sound transfer
What steps can I follow to achieve high levels of airtightness?
- Design for airtightness - ensure the architect designs the building with key airtightness details in mind. Keep it simple with the details
- Build for airtightness - Now that it is designed correctly, ensure all personnel who interact with the airtightness layer are trained and install products correctly. Workmanship can be validated with a WINCON test.
- Test for airtightness - We can only understand how something is performing by attaching a metric to it, airtightness is no different. Blower door test should be carried out to measure the airtightness.
Airtightness - The Facts
On average we spend up to 90% of our time indoors - it makes sense to make this environment as stable and comfortable as possible, free from any draught and cold spots.
Based on the envelope area of a 1,900 square foot certified Passive House If built just to building regulations (a leakage rate 10m3/hr/m2) the equivalent size hole in the building once everything has been sealed up would be approximately 440 x 440mm. Whereas what was achieved on this Passivhaus was a leakage area that is 10 times smaller at just 44 x 44mm
To put this leakage area into perspective, if a building was built to the backstop allowable leakage rate for building regulations, a hole in the wall the size of a typical ATM machine would still be an allowable leakage area whereas for an extremely airtight would only have a leakage area equivalent to that of a credit card.
This article is an abridged version of an original article published by By Niall Crosson, Senior Engineer, MEng Sc, BTECH, MIEI, CEPHC in June 2017
Achieving a reasonable level of airtightness is important for the energy efficiency of dwellings and the comfort of occupants. The benefits of improved insulation levels and more energy efficient heating systems are lost if warm air can leak out of a building and cold air can leak in energy, leaking energy is leaking money.
In the course of our day to day business we encounter plenty of customers, builders and trades who find U values a little confusing especially when it comes to understanding what the U value actually means and how it will affect or benefit the performance of a building, so we have compiled a brief 'U-Value for dummies' style explanation to help.