How to specify windows for your selfbuild project

Donna Muir, Workstream Lead, VELFAC Direct

Modern window technology can deliver a host of performance benefits to any self-build project, from vastly improved insulation to more natural light, and not  forgetting the ‘wow factor’ of big windows or glazed screens. It’s therefore important to think about windows right from the start of your planning process – here  are just some of the decisions you’ll have to make:

Where to place windows for optimum performance

The right windows in the right places will deliver an ideal ‘indoor climate’ all year round – no draughts or cold spots, full use of floor space right up to the glass,  and additional daylight throughout the home to help reduce energy bills. Work with your architect to determine ideal window placement, room by room, in  response to the way light changes throughout the day, and the year, and the impact of local shade. An effective window strategy will minimise overheating in  summer, maximise free heat from winter sun, and provide effective ventilation with the right mix of opening lights, trickle vents and possibly remote control high level windows.

Which frame material?

Consider all the options before making a decision:

  • Wood adds character, can be painted, stained or varnished, and is ideal for traditional and contemporary projects. It’s a good insulator, and  environmentally friendly, but has a naturally short lifecycle. Wood frames can be relatively thick, reducing light levels and insulation.
  • PVCu is low maintenance, affordable, offers good insulation and security, and is available in both solid colours and woodgrain effects. Thicker frames can  impact on window appearance, however, frames can discolour in sunlight, and lifetimes can be relatively short.
  • Metal windows are very low maintenance, have long lifetimes, offer great design versatility, and are very secure. They can look ‘cold and commercial’ in a  home, however, and systems offering slim frames and good insulation can be expensive.
  • Composite frames, combining external aluminium with internal timber, offer design versatility, ultra-slim frames, low maintenance construction and good  security. They can initially be more expensive, but are very cost effective as they don’t need repainting and are very energy efficient.

Double or triple glazing?

One of the most common questions asked of any window supplier and the answer – as you might guess – is ‘it depends’. Modern double glazing offers excellent  insulation, increased daylight and more ‘free’ heat from the sun, but there will be a difference in temperature closer to the window. Triple glazing allows slightly  less light and heat into a room, but retains internal heat more effectively resulting in a more balanced indoor temperature throughout the year.

Triple glazing can be up to 20 per cent more expensive, however, and is also heavier, limiting window size and possibly requiring a stronger wall construction. If  you can work out the ideal energy performance of your project – your architect or a specialist consultant can help you – this will determine whether you can meet your target with double or triple glazing, or if a mix of both will deliver the best result.

What’s the ideal frame colour – inside and out?

Your new windows should last for many years so choose frame colours which work in harmony with the rest of your house. The most popular external frame  colours are black, white and anthracite gray – colours which complement typical building materials such as brick, stone, or slate. In general dark colours can  make window frames ‘disappear’ into the glass, creating an uninterrupted façade, while brighter or lighter frames make a stronger impact, especially when sun  and shadow emphasise the contrast with the surrounding façade. Traditional internal frame favourites – white, neutral shades, or natural wood – help windows  blend into the room, reflect more daylight, and are easier to clean and touch up. Strong or dark internal colours make windows more prominent, adding interest  to open plan ‘white box’ interiors, but can show marks more quickly.

And finally – windows are expensive so how can I keep costs low?

Even though windows are an important investment, there are plenty of way to keep control of costs:

  • Mix double and triple glazing: Although triple glazing is more thermally efficient it’s also more expensive so consider mixing double and triple glazing for  ultimate performance, perhaps with triple glazing only on north-facing facades.
  • Choose cheaper opening functions: The lowest priced windows are those with the simplest opening functions, such as hinges at the side or top. Only install  other functions where they are needed – reversible windows where cleaning is difficult, for example. And does every window have to open? Consider  combining fixed and opening units to cut costs further.
  • More frame – more cost: Window pricing is based on length of frame, so if you plan on installing a large glazed area save money by specifying a few large  windows rather than multiple smaller units. You’ll also bring more natural light into the room and improve insulation, as glass is a better insulator than  frame.
  • Finishes and accessories? Go for standard options: Save money (and possibly reduce supply times) by choosing your supplier’s standard frame finish (and  you’ll probably still have a wide range of colours to choose from). Also only specify special accessories, such as child restrictors, where absolutely necessary.
  • Plan delivery carefully: If your windows are ready before you need them you might have to pay for specialist storage – talk to your builder and supplier to make sure delivery is scheduled accurately.
  • Can you reclaim VAT on your windows?: Some self-build new home projects qualify for VAT refunds on materials such as windows. Visit the HMRC website to find out if your project is eligible.

And finally – ask the experts before you start

Modern windows are very sophisticated, so avoid costly mistakes and consult with your architect and with potential suppliers before you place your order. Discuss every aspect of window performance and specification – including design, the ordering process, installation and after-sales support – to make sure the  windows you specify will deliver the performance you expect, and at a price you can afford.

To find out more about VELFAC product and services, please visit our website or contact our team at directestimating(Replace this parenthesis with the @ sign) or by phone at 01536 313 552