Sustainable Home Design & Green Home Design: 2024 Guide 

Throughout this guide we want to go through the different elements including: 

• Clever Planning & Design
• Insulation & Air Sealing 
• Energy Efficient Systems
• Water Drainage and Waste  
• Appliances & Electronics 
• Energy Audits 

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However, we should begin by outlining ‘The Future House Standard’ set of rules for sustainable homes that will come into effect in 2025 and also bring your attention to Passivhaus, which is a leading international design standard that you can work to and eventually certify your home as a sustainable home that uses minimal energy. 

Future House Standard 

The Future House Standard is a set of guidelines that must be followed for all new homes that are built in the UK from 2025 and onwards. These standards have been put in place to ensure that all homes being built will produce up to 80% less emissions than current properties across the country. The goal for these regulations is for all homes to maintain a comfortable temperature while producing the least amount of carbon emissions as possible. 

The requirements include all homes using a low carbon air source or ground source heat pump alongside effective natural ventilation. If this cannot be achieved, mechanical heat recovery systems might need to be included within the build. Properties must also be built with Solar PV Panels - from 2025 gas boilers will not be allowed to heat homes. 

Currently, this does not impact those wanting to renovate or extend their property.

This set of standards is only for new developments. However, it has been proposed that after the implementation of these rules in 2025, there should be a set of guidelines to those extending or renovating their property to include energy efficient replacements / repairs to their property.

Within the Future House Standard guidelines, the output of emissions a household makes is specified at a national level - I will explain this further below. However, the legislation includes the ability for local authorities to set their own standards. This is something that anyone wishing to build a new property should be aware of and make sure they are working to their local guidelines. 

Energy Metrics 

‘Primary Energy Consumption’ will be used as the primary measurement of building performance, with the amount of carbon dioxide emissions produced being the secondary measurement. 

The Primary Energy Consumption can be calculated by working out the energy potential of the fuel that goes into the power station to generate the electricity used within the home. 

The guidelines include a clear requirements for your properties energy efficiency through outlining the U Values for each property. 

U Values: Definition and Requirements 

The U Value of a home is the measurement of how well insulated your home is. The lower the U Value of your home, the better insulated your home is. So, the more effective your walls, roof, floor etc. are, the better your home is at retaining energy and therefore the more energy efficient your property will be. 

Currently there are no guidelines on what these U Values have to be in a property, but this is set to change. The minimum standards will be as follows: 

Wall: 0.18

Roof: 0.13

Floor: 0.13

Windows: 1.4

Doors: 1.0

Air Permability:5.0

Passivhaus 

When thinking about designing or creating a green home or a more sustainable home, people refer to Passivhaus and the international Passivhaus standard. 

Passivhaus is an international standard for homes which are designed to maintain a regular, comfortable temperature with minimal energy consumption. To achieve the Passivhaus Standard, your home must not exceed 15kWh/m2 and must stay within their guidelines for example, they have their own set of U Value metrics which are slightly more strict than those outlined above. But this is not all. 

The Passivhaus Standard has a very specific set of building requirements: 

• Very high levels of insulation
• Extremely high performance windows with insulated frames 
• The use of an airtight building fabric 
• ‘Thermal Bridge Free’ construction
• A mechanical ventilation system with highly efficient heat recovery 
• Accurave design using the Passive House Planning Package 

The Passivhaus Standard ensures a highly sustainable and energy efficient building, but is also not necessary to meet building guidelines in the UK. 

Instead, there are a number of different elements that you should consider from the very beginning of your project to improve the energy efficiency and sustainability of your property which is what we are going to go through in the following part of this article…

Clever Planning and Design 

Even from the very beginning with the design of your property, by considering the shape, size and orientation of a building, you can massively improve its energy efficiency. Beginning with orientation and passive solar design principals. Every property needs to make the most of natural sunlight, not only for daylight throughout the house but for heat. Ideally a property should be South Facing, so to make the most of sunlight all day, however, if the orientation of the plot doesn’t work like that, the home should consider how to make the most of south facing elements eg. the inclusion of more windows on the south facing facade. 

The way the building is designed and built is also important - there is a lot of research that clearly shows an optimised building envelope provides the property with the most emission friendly benefits. The building envelope is the separation of the shell of the building from the indoor space, providing a climate controlled environment. 

Insulation and Air Sealing 

On average 40% of heating and energy is lost through the gaps and cracks throughout our homes - 25% being typically through the roof! A sustainable home is clearly identified as a well insulated home. 

Insulation and air sealing are the key to success when it comes to designing and building a sustainable house. When building a new home, you can be very clever about this from the beginning. Choosing your build materials well, the envelope build style and maybe using the Passivhaus design guide a good baseline for your design and construction plan. 

For those of you who are attempting to improve the efficiency of the property you’re already living in, here are some elements that you need to consider: 

Cavity Wall Insulation - This is in reference to the gaps of air that are caught between the internal and external walls. You can insulate these walls using wood fibres, polystyrene or insulated boards (which are the best solution if you have large walls that need to be insulated). 

Loft insulation - With around 25% of properties energy being lost through the roof, having effective insulation in the loft space is a necessity to reducing your energy consumption. The best way to do this is by insulating between the joists which can be done by laying down blanket loft insulation rolls. 

Gaps in Floorboards - Old floorboards expand and contract depending on the temperature which can allow for a great loss of heat energy. The best way to prevent this happening is to fill in the gaps with resin, acrylic strips or wood filler strips. 

Draft Excluders & Window Seal Replacements - You need to avoid any drafts being allowed in from around doorframes, letter boxes or keyholes - this can be done by using foam, plastic or mental strips as draft excluders. It is also very important to replace the seals on all windows every 5 - 10 years as the seals will become less effective over time and begin to allow heat to escape. Replacing the window seal also prevents moisture building up around the windows which can create mould. 

Energy Efficient Systems 

There are many different energy efficient systems that can be included within a building to make it more energy efficient. We are going to be covering the main systems: 

1. Heat / Air Pumps 
2. Solar Energy 
3. Smart Thermostats 
4. Mechanical Ventilation / Heat Recovery Ventilation

Heat / Air Pumps 

Ground source heat pumps and air source heat pumps are the sustainable alternative to boilers. They work by extracting the heat from the air or the ground and transfer the fresh air back into your home. They eliminate the need for gas pipes and oil tanks. Although they are not the cheapest to purchase, there are government schemes in place to help so it is vital you check what is available if you are considering this within your build. 

Solar Energy 

You can incorporate solar energy into your property in two ways. You can include Solar PV Panels  or you can include the use of Solar Thermal Panels. 

Solar Photovoltic Installation convert sunlight straight into electricity which can be used to power or heat your home. They are a reliable and low maintenance sustainable energy system that can significantly increase the sustainability of your home. Although they do have high upfront costs for their purchase and installation, there are always government schemes and grants which help to finance purchasing solar panels for your home. 

Solar Thermal Panels are slightly different, as they look similar however, they collect the heat from the sun which you can use to heat your home or heat the water in your home. It can later be converted into electricity but this does not happen right away. 

Both of these systems can be used in conjunction with your current home systems or with any new sustainable systems you might want to incorporate into your property. 

Smart Thermostats 

Smart thermostats are one of the great benefits of new technology. We now have the ability to control the heating in our homes from our smart phones. By using a smart thermostat, we are able to maintain a moderate temperature in our homes while we are there and reduce the temperature of the home when they are not being used. 

Not only does this mean that homeowners can save money by reducing the amount of heating they are paying for, but by being able to have this much control over the heating system, we are able to massively reduce the amount of energy required to heat our homes. 

Mechanical Ventilation / Heat Recovery Ventilation

Heat Recovery Ventilation Systems are a super sustainable way of heating and cooling your home in the winter and the summer months. These systems work by removing the heat from the air in your kitchen or bathroom etc. in the winter, and use that heat to warm the fresh air coming in from the outside to heat your home. Alternatively, in the summer,HRV systems reverse this process by removing the heat from incoming fresh air, transferring it to the outgoing air. 

Heat Recovery Ventilation systems are a great way to achieve the main goal: achieving a maintained, comfortable temperature throughout your home while using the least amount of energy as possible. 

Water, Drainage & Waste 

Water consumption is a huge consideration for those that want to achieve a green home. In order to achieve a sustainable house, we want to include as many water saving measures as possible throughout the building. There are many different ways of achieving this, but the most obvious are to include low flush toilets and installation a water recycling system within your home. 

Sustainable home design also includes the attempt at creating a zero waste home (where possible). In order to achieve this, it is important to look for ways that you can re use household waste eg. composting or waste recycling. 

Appliances and Electronics 

Picking energy efficient appliances and electronics is an obvious way to reduce energy consumption within the household. When it comes to lights, you need to be looking for lights that have an A+++ ranking such as LED lights. LED’s not only use 80-90% less energy than a regular lightbuld, but they also last 12 times longer. 

When purchasing larger appliances, such as your fridge, freezer, dishwasher, washing machine etc. make sure the energy ranking is always A at least for it to be the most sustainable option. Remember, it might be slightly more expensive to purchase, but you will be saving money in the long run by creating a more energy efficient house - and it is much better for the environment! 

Government Costs and Incentives 

Always remember that in this ever changing landscape of green building and sustainable development, there are always new incentives and subsidies offered by the government to help fund the incorporation of renewable energy. These could be at a national level or there could be green initiatives local to you - make sure you do your research prior to purchasing. 

Consult with An Architect 

Alternatively, if you know you want to make your home more energy efficient but you’re not sure which of these solutions would work best for your property - or maybe you want to build a property and still are unsure of where to start… Speak to an architect today at Space That Inspires. We offer qualified advice with our experienced architects, for a one time fee with no further strings attached. 

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