Windows are one of the biggest investments when building or upgrading a house. They affect not only the look of the property but also its energy efficiency and comfort. Many homeowners are curious whether it’s more cost-effective to install brand-new windows in a new build or to replace the old ones in an existing house.
There is no simple answer – both options have their pros and cons, and the final cost depends on project size, materials and installation details. Fenbro knows these differences well, and in this article we’ll break them down to help you understand what really matters.
New build window installation – what does it involve?
Installing windows in a brand new build is usually a more straightforward process. Since there are no old frames to remove and no damaged walls to repair, fitters can work with clean openings designed specifically for the chosen window sizes. This makes the installation quicker, reduces the risk of mistakes, and helps achieve excellent airtightness from the start.
Another advantage of new build projects is flexibility. Homeowners can decide on larger glazing areas, sliding doors or modern window styles without being limited by the structure of an older property. The costs are also easier to predict because everything is planned at the design stage. However, there is one important thing to keep in mind: in a new build you usually need to purchase all windows at once, which means a higher one-time expense compared to replacing them gradually in an existing home.
Replacing windows in a house – challenges and costs
Window replacement in an existing home often comes with a different set of challenges. Unlike in a new build, the process starts with removing the old frames, glass and fittings. This step can reveal additional issues such as damaged plaster, rotten timber or gaps in the wall that need to be repaired before the new windows are installed. All of this adds time and labour costs.
Sealing and insulation are also more demanding in older properties. Installers have to work around existing structures, which makes it harder to achieve perfect airtightness and to avoid thermal bridging. Thresholds and sills frequently require extra attention to make sure the final result is both energy-efficient and durable.
For skilled professionals (such as the trusted fitting teams Fenbro cooperates with) these challenges are a standard part of the job. Thanks to their expertise, even older houses can achieve a modern look and excellent performance after window replacement.
On the positive side, replacement projects allow homeowners to modernise their property without the need for a complete rebuild. You can improve comfort, energy efficiency and the overall look of your house. Another advantage is flexibility in budgeting. Windows can be replaced gradually, room by room, which spreads the cost over time.
Cost comparison – new build vs renovation
When it comes to costs, the two scenarios differ in several important ways.
New construction window installation cost
New build installation is generally easier to price. Since windows are planned from the very beginning, the sizes match the design and the openings are prepared for fitting. There are no old frames to remove and no repairs needed around the reveals, which keeps the installation process straightforward. On the other hand, new build projects usually require purchasing all windows and doors at once, which means a significant one-time expense.
Window replacement cost
Window replacement in existing houses can sometimes be cheaper if you look at the cost of replacing only a few units. Replacement projects don’t require purchasing a full set of windows at once, which makes them more flexible for homeowners compared to new builds. However, the cost per unit is often higher than in new builds because it includes removal, disposal of old frames and potential repair work.Both approaches can vary widely in cost depending on the material (uPVC, aluminium, steel), the type of glazing, and the overall size of the project. That’s why real-life case studies are the best way to illustrate the difference.
Real life case studies from Fenbro customers
Numbers speak louder than theory. Here are four Fenbro projects, including new builds and renovations, that demonstrate the real costs of window installation in our customers’ homes.
Case 1 – New build in the Mayo area
- Scope: 16 uPVC windows in a newly built family home.
- Cost: approx. €3800–€4,000 net for fitting.
- Takeaway: straightforward installation into prepared openings kept the costs relatively low.
Case 2 – New build in the Dublin area
- Scope: 30 aluminium windows in a larger property.
- Cost: approx. €6,500–€7,000 net for fitting.
- Takeaway: larger orders naturally generate higher totals, but the cost per window remains efficient in new builds.
Case 3 – Renovation project in the Galway area
- Scope: 11 uPVC windows replaced in an older home.
- Cost: approx. €3,500–€3,800 net for fitting.
- Takeaway: removal of old frames and sealing work increased the per-unit cost compared to new builds.
Case 4 – Renovation project in the Limerick area
- Scope: 19 uPVC windows in an existing property.
- Cost: approx. €6,200–€6,500 net for fitting.
- Takeaway: as the project grows, renovation costs rise too, mainly due to dismantling and adjustments to the existing structure.
These projects prove that whether it’s a new build or a renovation, Fenbro customers can count on professional fitting and transparent pricing adapted to their needs.
Other factors to consider
Price is not the only element that matters when deciding between new build installation and replacement in an older property. Some additional factors can make one option more attractive than the other.
Airtightness and thermal performance
In new builds, achieving airtightness is simpler because the openings are designed for the selected windows. This helps avoid thermal bridging and ensures excellent insulation from the start. In older houses, fitters need to work around existing walls and thresholds, which makes proper sealing more challenging, though not impossible with experienced installers.
Design flexibility
A new build allows freedom when it comes to design. Large glazing areas, panoramic windows or contemporary frames can be included in the architectural plan without compromise. In contrast, replacement projects often need to adapt to the structure of the existing building, which may limit the size or position of windows.
Immediate impact and energy savings
Replacement projects deliver results right away. By swapping old, leaky windows for modern, energy-efficient ones, homeowners can quickly reduce heat loss, lower their energy bills and improve comfort without waiting for a full new build.
Conclusion: which option is more cost-effective?
There is no straightforward answer to whether new build installation or replacement is cheaper. It all depends on the size of the project, the type of windows and the overall budget.
At Fenbro, we support both scenarios with expert solutions tailored to our customers’ needs. New build or renovation, the result is the same: quality you can trust. Explore our wide range of windows and contact us today for a free quote. Experience the Fenbro difference!
Frequently Asked Questions (FAQ)
How much does it cost to put new windows in a house?
The cost depends on the size of the project, the chosen material (uPVC, aluminium, timber) and the glazing type. At Fenbro, all prices are calculated individually, but based on our experience new build installation is often more cost-efficient per unit because the openings are prepared in advance.
Is it cheaper to replace windows or install them in a new build?
Many online articles suggest that replacement windows are cheaper overall. However, Fenbro’s experience shows that new builds are more cost-efficient per unit, while replacements involve removing old frames and often repair work – but they offer flexibility and remain very popular with customers in Ireland and the UK.
Do new windows add value to a home?
Yes. High-quality windows reduce energy bills, improve comfort and security, and increase resale value. Fenbro supplies a wide range of energy-efficient windows and doors designed for both new builds and renovations.
