Successful window specification: What you need to think about
25th September 2021
Successful window specification: What you need to think about
by Gordon Heron, Business Development Manager, Eurocell
When it comes to the effective specification, design and installation of windows, several key factors need to be carefully considered.
In Eurocell’s experience, critical areas such as thermal performance and ventilation, product design, use and finish, adherence to current standards and regulations, security and safety, installation, and cost, should be the primary focal points of discussion and planning to create and deliver an efficient, cost effective, high performing window and door solution.
From working with many architects, specifiers, contractors, and fabricators it is clear that by carefully considering the following areas, the best results can be ultimately achieved.
Thermal performance & ventilation
Both the required thermal performance of windows and the ventilation needed in occupied spaces are key priorities to ensure comfortable living and working experiences within buildings.
When thinking about the necessary U-value of solutions to prevent heat loss, specifiers must also consider the effect on the G-value of the glazing to be specified which measures how much heat is likely to enter the building as a result of Solar Heat gain. The balancing act between heat loss and space overheating is important when it comes to the long-term effectiveness of the scheme. This is growing in importance as the Future Homes Standard looks to tighten the regulations around thermal performance of buildings.
Likewise, ventilation requirements must be carefully considered. The Future Homes Standard lays down specific criteria concerning the amount of ventilation required for living spaces and this significantly impacts the types and sizes of final window and door specification.
Solutions for medium or high-rise developments must consider critical safety aspects and design in window solutions that are safe to use at high levels, as well as provide the ventilation demanded by occupants. Questions around natural or mechanical ventilation will influence specification choice too, with the need to avoid moisture or stale air build up.
Design, finish & acoustics
Chief among the consideration points for windows will be the choice of colour and style to enhance the aesthetics and visual appeal of the building. Is a white or coloured foil finish required? What about the joints? If situated in a coastal environment, then fixings will have to be stainless steel to combat the effect of salt water in the air.
What about the prevailing cleaning strategy? Are occupants expected to undertake their own window cleaning, which can mean a move towards tilt and turn or reversable windows? However, if it is an external cleaning regime, perhaps alternative and value engineered window designs will suffice?
With brownfield sites and urban locations increasingly prone to noise pollution from nearby busy roads and rail lines, the acoustic performance of the window solution needs to be a top priority.
Again, existing regulations are clamping down on residual noise level acceptance and forcing specifiers to satisfy ever tighter criteria. But the noise reduction requirements between low- and high-level dwellings are markedly different and need to be factored into development planning, where disparate needs may enable specific product choice flexibility and potential cost reduction.
Finally, linked to the U- and G-value considerations, the weight of glass and glazed units must be noted. Can the system take the weight of glass specified to meet thermal, ventilation and acoustic demands?
When it comes to installation, the specification decision process needs to cover several key areas. This includes assessing the wind load on the development and whether the window solution can satisfactorily deliver the performance needed when exposed to the elements.
A focus on the style of building also underscores specification decision making. Is it a concrete frame or brick and block style of construction, and do the windows require direct fixing or fixing with straps? What about the interface detail and the sought-after external finish, and do the windows work seamlessly with the desired aesthetic look of the façade?
Assurances should be sought around meeting the on-site programme scheduling for installation. Product solutions such as aluminium frames often have longer lead times than PVC-U and specifiers should ensure that the manufacturing and installation supply chain can meet their timescales. If not, switching specification can open the opportunity to speed-up completion and meet pressures to deliver a finished development.
As touched upon earlier, safety and security aspects are vital for window specification. In settings such as care homes for instance, solutions may need to consider the need to provide restrictive use so that potentially vulnerable residents are not exposed to dangers around window openings.
Accreditation is also important, and the specification team needs to be clear about the standards the final scheme must adhere to. The rigorous use of testing must be factored in, and this can range from on-site water testing that underpins wind, weather, and security aspects, to ensuring all current regulations are satisfied across a range of criteria.
The successful specification of windows and door solutions that will form an integral part of the overall scheme, requires a detailed assessment of many important areas ahead of any final decisions.
Eurocell has in-depth experience of working alongside specification teams to help guide them through what can be challenging technical, regulatory, design, and installation stages.
But by being aware of the many facets that make up an effective window and door specification solution, architects, specifiers, and fabricators should be better placed to overcome the common challenges they face and arrive at a specification choice that delivers long lasting, high-quality, cost-effective performance.
If you want us to help you with your specifications, please contact us on 0300 333 6525.