Window Cost Guide

Whether you're costing new windows for your self-build, or replacing fenestration in your current property, here's how to estimate the price

by Adrian Wild

16th April 2018

The windows you specify for your new build or renovation will have a big impact on the house’s final aesthetic – so it’s worth spending plenty of time on the planning stages to ensure you get this part of your project right.

Buy cheap, buy twice is an apt adage in this market. Poor-quality designs will not only compromise the look, but they’ll also fall down in terms of durability and longevity. So it’s worth paying extra for a first-class product – and there are options across the board in terms of PVCu, softwood, hardwood and aluminium (plus composites, although we haven’t priced them here).

The standard of the manufacturing process can vary massively, both across the UK and abroad, so make sure you do your research. In the PVCu sector, for instance, the quality of the blending, extrusion, injection moulding, foil finishing, colour matching and other criteria will all make a significant difference to the lifespan and therefore future maintenance and replacement costs.

In the first instance, look at the obvious requirements. Does the manufacturer’s warranty extend to at least 10 years, for instance. It’s also important to check if it includes any cover on finishes and fittings. Do the products carry a BSI Kite Mark and have they been assessed by the British Board of Agrement (BBA)? Is the manufacture and supply carried out under the ISO 9001 quality management system?

This engineered softwood flush casement window by Kloeber is painted in Storm Grey

Produced by Lomax + Wood, these windows feature aluminium-clad timber flush casements

Check, too, whether the windows are properly tested in terms of delivering on the performance standards you’re specifying for your project, such as for security (governed by Part Q of the Building Regulations).

There’s a host of considerations to account for when choosing between different frame materials, but here’s a quick guide to the main areas to look at:

PVCu is the cheapest up front, but there’s a huge variance in prices depending on quality. It is low maintenance, but not as durable as the alternatives; replacing rather than repairing is generally the norm.
Softwood windows can offer a very good lifespan, although they will need more maintenance than PVCu. Look for products that provide a lengthy warranty on
the factory finish (six years is commonplace on stains; longer on paint) to reduce ongoing costs for upkeep.
Aluminium products are ultra-low maintenance thanks to their corrosion resistant coatings, meaning the frame is easy to care for. The metal will not swell, crack, split or warp over time; ensuring an extended product life. Their growing popularity makes them competitive price-wise.
Hardwood is a slow-growing, expensive material, so the initial costs will be greater. However, you get the benefit of a very stable timber window offering excellent durability. As with softwood, these units come with protective coatings to maximise the lifespan.

Window cost comparison

The tables below set out typical base prices for the different material types. Naturally, your costs will vary significantly depending on the quality of the unit and specification you go for. These figures are based on a 1,200mm x 1,200mm double-glazed, double-opening casement that would meet Building Regulations.