Architecture: What You Need to Know About Building an Eco Home
Curious about sustainable design and building an environmentally friendly home? From standards to costs, three experts address top questions
An environmentally friendly home, designed and built in a sustainable way, that saves energy and money as you live in it… What’s not to like? With eco homes becoming increasingly popular, it’s clear that the quest for a beautiful yet sustainable home is one many of us aspire to.
But when it comes to sustainable design and construction, practical ways of saving energy, and giving your home a low carbon footprint, it can all begin to seem quite complicated. Do you have to build to a particular standard and, if so, which one should you choose and why? Can you do an eco-build extension or refurbishment of an existing property? And how much more does it really cost to build an eco home, and is this reflected in its market value or reduced cost of living in it?
Three experts with hands-on experience of designing, project-managing and building eco homes answer some key questions and share their advice on the essential information you need to know about building an eco home.
Professional advice from:
Alan Budden of Eco Design Consultants
Ryan von Ruben of Harris Calnan Construction
Paul Younger of Hewitt Studios
But when it comes to sustainable design and construction, practical ways of saving energy, and giving your home a low carbon footprint, it can all begin to seem quite complicated. Do you have to build to a particular standard and, if so, which one should you choose and why? Can you do an eco-build extension or refurbishment of an existing property? And how much more does it really cost to build an eco home, and is this reflected in its market value or reduced cost of living in it?
Three experts with hands-on experience of designing, project-managing and building eco homes answer some key questions and share their advice on the essential information you need to know about building an eco home.
Professional advice from:
Alan Budden of Eco Design Consultants
Ryan von Ruben of Harris Calnan Construction
Paul Younger of Hewitt Studios
2. To what standards can eco homes be built?
There’s a range of different ways to accredit eco homes. These provide certain standards and then certify that a building meets them. Standards can be more stringent or more relaxed, depending on whether you are aiming for a truly zero-carbon house or simply a more sustainable and environmentally friendly home. The right standard for you will depend on your needs and wishes.
Popular standards in the UK include the Code for Sustainable Homes and Passivhaus (both of which you’ll find out more about as you read on) among other options. If your planning permission depends on achieving a particular standard, this may require you to meet a certain Code level. Or you may decide that you have a preference for one approach over the other.
There’s a range of different ways to accredit eco homes. These provide certain standards and then certify that a building meets them. Standards can be more stringent or more relaxed, depending on whether you are aiming for a truly zero-carbon house or simply a more sustainable and environmentally friendly home. The right standard for you will depend on your needs and wishes.
Popular standards in the UK include the Code for Sustainable Homes and Passivhaus (both of which you’ll find out more about as you read on) among other options. If your planning permission depends on achieving a particular standard, this may require you to meet a certain Code level. Or you may decide that you have a preference for one approach over the other.
3. What is the Code for Sustainable Homes?
The Code is a government scheme that works by awarding a new home a rating from Level 1 to Level 6. The rating is based on the home’s performance against nine sustainability criteria, which are combined to assess the overall environmental impact. Level 1 is entry level above building regulations, and Level 6 is the highest, reflecting a zero-carbon home that meets the highest standards of sustainability.
The sustainability criteria against which new homes are measured by the Code are: energy and carbon emissions; water; materials; surface water run-off; waste; pollution; health and wellbeing; management; and ecology.
‘One of the things about the Code system is that it takes a holistic approach,’ explains Paul Younger. ‘This means that requirements can include things relating to home security, or to accessibility and making sure a house is suitable for use over a whole lifetime as the occupant ages – a hallway that’s wide enough for a wheelchair, say, or stairs you can convert for a stairlift. These are very good standards, from a homeowner’s point of view, but not necessarily right for somebody who wants to focus solely on carbon footprint or sustainability.’
The Code is a government scheme that works by awarding a new home a rating from Level 1 to Level 6. The rating is based on the home’s performance against nine sustainability criteria, which are combined to assess the overall environmental impact. Level 1 is entry level above building regulations, and Level 6 is the highest, reflecting a zero-carbon home that meets the highest standards of sustainability.
The sustainability criteria against which new homes are measured by the Code are: energy and carbon emissions; water; materials; surface water run-off; waste; pollution; health and wellbeing; management; and ecology.
‘One of the things about the Code system is that it takes a holistic approach,’ explains Paul Younger. ‘This means that requirements can include things relating to home security, or to accessibility and making sure a house is suitable for use over a whole lifetime as the occupant ages – a hallway that’s wide enough for a wheelchair, say, or stairs you can convert for a stairlift. These are very good standards, from a homeowner’s point of view, but not necessarily right for somebody who wants to focus solely on carbon footprint or sustainability.’
4. What is Passivhaus?
Passivhaus is an international low-energy design standard. Heat loss from Passivhaus buildings is minimised to the extent that they hardly need any heating at all and often do without a conventional heating system. ‘The Passivhaus standard has more of an emphasis on the building fabric,’ explains Paul Younger. Particularly popular in Germany and Scandinavia, there are thousands of Passivhaus homes in the UK and across Europe.
A Passivhaus can be built using almost any construction system; it just has to meet certain standards of low-energy space heating demand. A house built to Passivhaus standards will typically feature serious insulation, triple-glazed windows with insulated frames, amazing airtightness levels and mechanical ventilation with heat recovery.
Clever design also features, making the most of the natural world to ensure a house works perfectly in terms of heat and light. ‘Clever design and positioning can mean you get a net heat gain from south-facing windows,’ says Alan Budden. ‘But then you need to be careful not to oversize them, in terms of getting too much heat in summer. It’s quite a complex calculation to get the balance right.’
Passivhaus is an international low-energy design standard. Heat loss from Passivhaus buildings is minimised to the extent that they hardly need any heating at all and often do without a conventional heating system. ‘The Passivhaus standard has more of an emphasis on the building fabric,’ explains Paul Younger. Particularly popular in Germany and Scandinavia, there are thousands of Passivhaus homes in the UK and across Europe.
A Passivhaus can be built using almost any construction system; it just has to meet certain standards of low-energy space heating demand. A house built to Passivhaus standards will typically feature serious insulation, triple-glazed windows with insulated frames, amazing airtightness levels and mechanical ventilation with heat recovery.
Clever design also features, making the most of the natural world to ensure a house works perfectly in terms of heat and light. ‘Clever design and positioning can mean you get a net heat gain from south-facing windows,’ says Alan Budden. ‘But then you need to be careful not to oversize them, in terms of getting too much heat in summer. It’s quite a complex calculation to get the balance right.’
5. What other options exist?
There are a number of other standards, both national and global, that you could choose to build to. But make sure you are working to a reputable standard. ‘Many certification systems, including the Code for Sustainable Homes, are based around research that originates from the Building Research Establishment (BRE), so it is authoritative and scientific,’ says Ryan von Ruben.
‘Deciding on what standard to build to will really depend on what you’re trying to achieve,’ says Paul Younger. ‘Some planning permission will ask for a particular Code level, for example a Code 3 as a minimum. Then you’ll need to work with a Code assessor to draw up targets and strategies to meet the requirements of the Code you’re working towards.’
If you don’t need it for planning permission, it’s also possible to follow recommendations and best practice, or to choose a prefabricated house that meets many of the standards, but not actually pay extra to have the house formally accredited to a particular standard.
There are a number of other standards, both national and global, that you could choose to build to. But make sure you are working to a reputable standard. ‘Many certification systems, including the Code for Sustainable Homes, are based around research that originates from the Building Research Establishment (BRE), so it is authoritative and scientific,’ says Ryan von Ruben.
‘Deciding on what standard to build to will really depend on what you’re trying to achieve,’ says Paul Younger. ‘Some planning permission will ask for a particular Code level, for example a Code 3 as a minimum. Then you’ll need to work with a Code assessor to draw up targets and strategies to meet the requirements of the Code you’re working towards.’
If you don’t need it for planning permission, it’s also possible to follow recommendations and best practice, or to choose a prefabricated house that meets many of the standards, but not actually pay extra to have the house formally accredited to a particular standard.
6. What features might an eco home include?
With an energy-conscious outlook, an eco home is likely to include a number of features designed to make it sustainable to build and run.
These could include renewable energy systems, sustainably produced and highly effective insulation, triple glazing, solar panels, a geo-thermal heat pump, rainwater harvesting systems including perhaps a green roof planted with wild flowers, energy-efficient lighting, ventilation systems with heat recovery, and more.
With an energy-conscious outlook, an eco home is likely to include a number of features designed to make it sustainable to build and run.
These could include renewable energy systems, sustainably produced and highly effective insulation, triple glazing, solar panels, a geo-thermal heat pump, rainwater harvesting systems including perhaps a green roof planted with wild flowers, energy-efficient lighting, ventilation systems with heat recovery, and more.
7. Is it possible to do an eco-build extension or refurbishment?
Yes, it’s possible. But because you’re working with a pre-existing building, it’s not quite as straightforward as the blank canvas a new build provides. It’s especially complicated when it comes to building to a particular standard.
‘Passivhaus is the main standard we aspire to,’ says Alan Budden. ‘But if we’re working on a refurbishment of an existing house, the EnerPHit standard may be more appropriate.’ The EnerPHit standard was developed as a good practice refurbishment guide for Passivhaus-style renovations, and takes into account the limitations of working with an existing building.
Check out what you need to consider when planning a rear extension
Yes, it’s possible. But because you’re working with a pre-existing building, it’s not quite as straightforward as the blank canvas a new build provides. It’s especially complicated when it comes to building to a particular standard.
‘Passivhaus is the main standard we aspire to,’ says Alan Budden. ‘But if we’re working on a refurbishment of an existing house, the EnerPHit standard may be more appropriate.’ The EnerPHit standard was developed as a good practice refurbishment guide for Passivhaus-style renovations, and takes into account the limitations of working with an existing building.
Check out what you need to consider when planning a rear extension
8. What are the costs of building an eco home?
As with any building project, costs can vary wildly depending on the specification. Will it cost more to build an eco house? Not necessarily.
‘If you build to the Code, you may be looking at a somewhat higher build cost than for an equivalent new build that isn’t ecofriendly,’ says Paul Younger. ‘It can cost 5% to 15% more. Passivhaus, meanwhile, suggests houses can be built to its standards with no price cost increase.’
As with any building project, costs can vary wildly depending on the specification. Will it cost more to build an eco house? Not necessarily.
‘If you build to the Code, you may be looking at a somewhat higher build cost than for an equivalent new build that isn’t ecofriendly,’ says Paul Younger. ‘It can cost 5% to 15% more. Passivhaus, meanwhile, suggests houses can be built to its standards with no price cost increase.’
9. What’s the value of eco homes?
House prices can vary enormously depending on the location, size and even interior design, so it’s hard to make generalisations about whether eco houses have a higher market value. Some would say they don’t, while others would argue that the energy-efficiency of eco homes makes them more desirable to potential purchasers.
‘We worked on a development of nine eco houses in Bath, all zero carbon and built to a Code 5 standard,’ says Paul Younger. ‘Interestingly, we had a lot of debate with the estate agents, who initially didn’t value the properties any differently from others of the same size in the area. But when they actually started to market the scheme and promote the benefits of eco housing, this did translate into higher sale prices.’
House prices can vary enormously depending on the location, size and even interior design, so it’s hard to make generalisations about whether eco houses have a higher market value. Some would say they don’t, while others would argue that the energy-efficiency of eco homes makes them more desirable to potential purchasers.
‘We worked on a development of nine eco houses in Bath, all zero carbon and built to a Code 5 standard,’ says Paul Younger. ‘Interestingly, we had a lot of debate with the estate agents, who initially didn’t value the properties any differently from others of the same size in the area. But when they actually started to market the scheme and promote the benefits of eco housing, this did translate into higher sale prices.’
10. What’s it like to live in an eco home?
The experience of actually living in an eco home is unique. As you might expect, running costs will be significantly cheaper because of the lower energy use. ‘Over three years, the energy cost will typically be £1,000, while the income from photovoltaic cells could itself bring in £2,000,’ explains Paul Younger. ‘So there can be significant long-term savings on the running costs of the house.’
You can also expect the climate in the house to be regulated more smoothly, with less variation. ‘The other thing that comes with an eco house is comfort,’ points out Alan Budden. ‘When you live in an eco house, it will be comfortable, particularly in terms of temperature. You should be able to sit right beside the window on a cold day and still be a reasonable temperature.’
The experience of actually living in an eco home is unique. As you might expect, running costs will be significantly cheaper because of the lower energy use. ‘Over three years, the energy cost will typically be £1,000, while the income from photovoltaic cells could itself bring in £2,000,’ explains Paul Younger. ‘So there can be significant long-term savings on the running costs of the house.’
You can also expect the climate in the house to be regulated more smoothly, with less variation. ‘The other thing that comes with an eco house is comfort,’ points out Alan Budden. ‘When you live in an eco house, it will be comfortable, particularly in terms of temperature. You should be able to sit right beside the window on a cold day and still be a reasonable temperature.’
11. How can I get the design right?
Commissioning an architect to create a design that’s specific to your needs and site is one option. Alternatively, you could consider working from an existing design or using a prefabricated frame, which can save significantly on initial outlay.
‘Consider an off-the-peg timber frame system that comes with some Code For Sustainable Homes or Passivhaus accreditation,’ recommends Paul Younger. ‘For instance, we built a house on the Gower costing less than 5% more than a non-environmentally friendly new-build would have. If you want a relatively conventional house design, it can reduce your costs and give you definite standards of airtightness and insulation.’
Commissioning an architect to create a design that’s specific to your needs and site is one option. Alternatively, you could consider working from an existing design or using a prefabricated frame, which can save significantly on initial outlay.
‘Consider an off-the-peg timber frame system that comes with some Code For Sustainable Homes or Passivhaus accreditation,’ recommends Paul Younger. ‘For instance, we built a house on the Gower costing less than 5% more than a non-environmentally friendly new-build would have. If you want a relatively conventional house design, it can reduce your costs and give you definite standards of airtightness and insulation.’
12. Is an architect essential?
If you want to build a totally bespoke home, or adapt an existing design to your own specification, then you will need an architect. The expertise an architect can bring won’t just be related to design, but to their experience of working on similar projects in the past.
‘Architects will have experience of dealing with a range of different new technologies,’ says Ryan von Ruben. ‘They will have come across some things they think are worthwhile, and others they have found create more problems than they solve. That’s the experience you’re looking for.’
Discover what you need to consider before hiring an architect
If you want to build a totally bespoke home, or adapt an existing design to your own specification, then you will need an architect. The expertise an architect can bring won’t just be related to design, but to their experience of working on similar projects in the past.
‘Architects will have experience of dealing with a range of different new technologies,’ says Ryan von Ruben. ‘They will have come across some things they think are worthwhile, and others they have found create more problems than they solve. That’s the experience you’re looking for.’
Discover what you need to consider before hiring an architect
13. Do I need a specialist builder?
Your choice of builder is definitely as important as the architect or house design you choose. ‘If you want to be environmentally friendly, then choosing who you use to build your project can be the most important thing,’ explains Ryan von Ruben. ‘It’s not just about using materials from sustainable sources, but about having the expertise to work with them, and about managing construction waste in an environmentally friendly way, which means tracking it and recycling it appropriately.’
If you are working with an architect or a design firm, they may already have experience of working with builders whom they would recommend. If you are sourcing a builder independently, you may want to ask about their past experience of working on eco homes, and of working with any of the key materials or technologies you plan to use.
Your choice of builder is definitely as important as the architect or house design you choose. ‘If you want to be environmentally friendly, then choosing who you use to build your project can be the most important thing,’ explains Ryan von Ruben. ‘It’s not just about using materials from sustainable sources, but about having the expertise to work with them, and about managing construction waste in an environmentally friendly way, which means tracking it and recycling it appropriately.’
If you are working with an architect or a design firm, they may already have experience of working with builders whom they would recommend. If you are sourcing a builder independently, you may want to ask about their past experience of working on eco homes, and of working with any of the key materials or technologies you plan to use.
14. Are we all looking at an environmentally friendly future?
‘The big falsehood about eco building is that it’s something you have to opt in to,’ says Ryan von Ruben. ‘Everyone’s suffering from latent guilt about whether they’re going to be “eco” enough. But the current building regulations already set out some stringent requirements. What people should realise is that anyone embarking on a new construction project in the UK these days will already be doing something that – in comparison with 10 years ago – is going to be a very ecofriendly project.’
TELL US…
Do you aspire to build your own eco home? Or are you already living the dream? Share your experiences, dilemmas, and successes in the comments below.
‘The big falsehood about eco building is that it’s something you have to opt in to,’ says Ryan von Ruben. ‘Everyone’s suffering from latent guilt about whether they’re going to be “eco” enough. But the current building regulations already set out some stringent requirements. What people should realise is that anyone embarking on a new construction project in the UK these days will already be doing something that – in comparison with 10 years ago – is going to be a very ecofriendly project.’
TELL US…
Do you aspire to build your own eco home? Or are you already living the dream? Share your experiences, dilemmas, and successes in the comments below.
An eco house is an environmentally low-impact home. This means it’s designed and built using materials and technology that reduce the carbon footprint and energy needs of the house.
‘The focus is on energy, which is natural because your carbon footprint is a measure of how much energy you’re consuming,’ says Ryan von Ruben. ‘But it’s not just about energy consumption. It also ranges from how the building is designed to how it’s constructed, and then to how it’s eventually used. It’s about the big picture.’