Based on Green Home’s Festival event “Start Saving on Energy” with BE-ST:

Improving the energy efficiency of your home can be daunting – it’s not always clear which measures are worth the investment. You want to be sure any steps you take are the right ones for your home.

Here’s a guide to getting started.

What is Home retrofit?

When we talk about home retrofit, we mean fitting new energy efficiency measures and technology into your home, such as additional insulation, underfloor heating or a heat pump. This is to achieve better energy efficiency – which means lower bills, more comfort and less reliance on fossil-fuels. 

Often when homeowners think about improvements, they focus on aesthetic upgrades or achieving more space. Retrofitting is about making the space you already have more comfortable, healthy and efficient.

1. Understand you Home

Buildings are complex and work differently so it’s helpful to understand how your home works. 

You can start by identifying the type of wall construction. These usually fall into one of three categories. 

  1. Traditional solid wall construction is made from stone, with floor beams/joists supported from within the stone wall. (usually built before 1919)
  1. Masonry cavity wall construction consists of two layers of brick or concrete blocks separated by a cavity (usually mid 20th century)
  1. Timber frame construction is built with timber, but may have an outer facade of masonry (usually 1980s onwards)

Different wall constructions have different requirements and risks. For example, traditional solid wall buildings require sensitive treatment as they absorb rain and internal humidity. They need vapour permeable materials such as lime-base pointing and lime plaster. You can find more information in this short guide from Historic Environment Scotland.

2. Repair and Maintain

If your home is in disrepair, this will undermine any energy efficiency improvements you make. Regular checks can help you identify what repairs are needed early. Prioritising repair and maintenance avoids big, unexpected costs down the road and means you get the best out of your existing fabric. 

It’s recommended you get a professional survey once every five years, and you can also perform a DIY surveys with the help of this tool from the charity Under One Roof.

3. Quick and Easy Draught-proofing

If you live in a cold and draughty house, some basic DIY draught-proofing can improve your comfort and lower your heating bills. 

The best time to identify draughts is on cold, windy days when your heating is on. You can run your fingers along edges to feel for cold air coming in, or use a smoke stick. Likely sources of draughts are under window ledges, around windows and doors, skirting boards, floorboards and loft hatches.

There are many options for DIY draught-proofing. You can use caulk or sealant (you will need a caulk gun) or purchase seals, tapes and draught excluders from hardware shops or online. If you have a fireplace, use a chimney balloon or chimney sheep to stop warm air in your house getting drawn up through the chimney. If you live on the ground floor with draughts coming through the floorboards, you can either caulk them or lay down an airtight membrane under a carpet.

Whenever you improve airtightness, it’s important to consider controlled ventilation in parallel…

4. Controlled Ventilation

Ventilation is important for air quality and moisture control, as it replaces humid, stale air with fresh air. When you improve airtightness, you need to make sure there is still adequate ventilation or you risk poor quality air and mould. 

You want to maintain relative humidity between around 40% and 65%. Too dry is uncomfortable. and too humid raises the risks of condensation, mould and pests such as silverfish. 

Ideally you want the right ventilation in the right areas at the right time: controlled ventiliation. One of the best ways to achieve this is with a Mechanical Ventilation with Heat Recovery system (MVHR) which manages humidity and recovers heat, giving you the best of both worlds: warm, fresh air without heat loss. However this can be expensive and disruptive in existing homes.

A basic way to ventilate an airtight home is simply to open windows on opposing sides of your home and create cross ventilation, once or twice a day. You can use a humidity moniter (hydrometer) to check when you need to do this, with special attention to kitchens and bathrooms.

However to avoid the inconvenience of manually controlling ventilation, a good option is to have simple quiet, low speed, continuous extraction fans in bathrooms and kitchens which will ventilate the whole house by drawing fresh air through the home from trickle vents in living spaces. 

5. Improve your Insulation

For effective insulation you need a continuous envelope with no gaps (thermal bridges), good thicknesses (or u-values) and appropriate materials for your home.

If you have a loft, it is worth checking how thick your loft insulation is. You want at least 300mm and no gaps where the rafters are. 

For your windows, there are other options to getting brand new windows. You might consider getting faulty window panes with condensation repaired or replaced, using window insulation film or secondary glazing. Secondary glazing is an especially good option for heritage windows which cannot be upgraded.

To inspect your wall insulation, you can purchase a cheap borescope which connects to your phone, and drill a small hole in the area of the wall you want to inspect (and repair later with a wall patch). Alternatively, your local tool library might have a thermal imaging camera which can give you some indication of where insulation is damaged or missing, or you can pay for professional thermal imaging services.

If you have a masonry cavity wall, a pattern of drill holes on the outside will indicate that the cavity has been insulated. 

We recommend taking independent advice before installing any form of wall insulation.

6. Optimise your Boiler

To get the best efficiency from your condensing boiler, turn the flow temperature down to around 50-60 degrees. To learn how to do this and how it helps your boiler work, watch our webinar on boiler efficiency.

7. Get Independent Advice – beware scammers

Home-owners will often get advice directly from installers and contractors and can sometimes end up with inappropriate measures for their home. At worst, this can mean getting scammed. For example, a dishonest installer might tell you there are government grants available to reclaim the money you spend on their products and services. 

The wrong measures for your home can lead to further problems, for example internal wall insulation creating damp. This can lead to spiralling costs and leave your home in a worse condition.

In order to achieve good retrofit results, it’s important to be aware of conflicting interests and seek independent advice (for example, from Loco Home). You also want to use trusted contractors and installers where possible.

8. Make a Long-Term Whole House Plan

It’s sensible to consider retrofit measures before you decorate or renovate. This enables you to co-ordinate work, for example improving your insulation while upgrading the kitchen. If you have a retrofit plan in place before making other changes to your home, it can minimise excess costs and disruption.

Buildings are complex systems and whole house planning takes into consideration how measures can impact your home in different ways. For example, sometimes when homeowners purchase new windows, it brings airtightness to a level where damp becomes a problem. So a whole house plan would bring in controlled ventilation in parallel.

To make a whole house plan for your home, book a home assessment with a retrofit planner today.

Home Assessments provide independent whole house planning and advice. Loco Home Retrofit CIC is an independent, non-profit climate action co-operative set up to help homeowners in Glasgow get off fossil fuels for good.

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