Online Configurator
Home extensions, made simple.
We've taken the guesswork out of extending your home. You design it online and see the price on screen, then we build it using Structural Insulated Panels, precision manufactured off-site to your exact specifications.
SIP's deliver exceptional U-values, airtightness and rapid on-site assembly, giving you a sustainable, high performance build with less waste and less time to construct.
Three steps to your new extension.
We visit your home to measure and finalise your design
View our process →Start your modular construction
View projects →Speed
Weeks not months, from groundworks to handover.
Because the wall and roof panels are fabricated off-site while your groundworks are underway, both timelines run in parallel. The shell goes up in days, not weeks, making it weathertight long before traditional methods.
- Wk 1Groundworks01Foundations
- Wk 2Modular Structure02SIPs erected
- Wk 3-4Extension Completed03Finished Extension
Trusted trades
A reliable, skilled network, managed end-to-end.
Every Gleneaston extension is project-managed by us, built with trade partners we've worked with for years: joiners, electricians, plumbers, plasterers, tilers. One point of contact from the first quote to the final handover. No subcontractor chain to navigate, no surprises on completion day.
…a sample of our extensions completed across Dublin & Kildare.
SIPs
Structural Insulated Panels engineered for performance.
A SIP is a single sandwich panel: two structural OSB boards bonded to a thick insulation core. Each panel arrives on site pre-cut based on your design specifications. The result is a highly insulated, airtight shell built in a fraction of the time of traditional methods, with the cross-section detail below.
- 1Plasterboard
- 2Service cavity
- 3OSB structural board
- 4EPS insulation core
- 5OSB structural board
- 6Ventilated cavity
- 7Render finish
The 3D model — drag to rotate, tap Exploded view to see the seven layers separate.
Why SIPs
Four reasons Irish homeowners are switching to SIPs.
Energy performance
An engineered EPS core delivers wall U-values of 0.14 to 0.18 W/m²K, comfortably ahead of TGD Part L 2022. That translates directly to an A-rated BER and lower running costs for the life of the extension.
Airtight & consistently warm
SIPs form a continuous, sealed envelope built for Irish weather. NSAI-certified test data shows SIP builds routinely achieve 1.5 to 3.0 m³/hr/m² at 50Pa, comfortably ahead of TGD Part L 2022's 5.0 maximum. The heat you pay for stays inside and every room holds a steady temperature.
Speed to build
Every panel is fabricated in the factory in parallel with your groundworks, so the shell can be weathertight within days of delivery. Fewer weather delays, less time on site, and a predictable programme from start to handover.
Sustainable by design
Each SIP panel locks carbon into the fabric of your home. A typical single-storey extension sequesters over 800 kg of CO₂. Factory precision cuts construction waste by around 35%, aligning with Ireland's Climate Action Plan and the shift toward Modern Methods of Construction (MMC).
Common questions
Everything you need to know
before you start designing.
How much does a Gleneaston extension cost?
The price you see in the online configurator is the price you pay, fixed and fully itemised in your PDF quote. Costs vary by size, finish and door / roof choices; a standard single-storey extension starts around €36,000 ex VAT for the base specification.
Do I need planning permission?
Most rear extensions under 40 sqm are exempt from planning permission for a regular detached or semi-detached house under the current Irish Planning and Development Regulations. We confirm this with you on the first site visit; if planning is required, we'll guide you through it.
How long does it take to build?
Most single-storey rear extensions are on site for 3 to 4 weeks from foundation pour to handover. Lead time from booking to the start of on-site work is typically 6 to 8 weeks.
What's included in the quote?
Everything from foundations and structure through to plastered walls, flooring, electrics, doors and roof finishes exactly as configured.
What areas do you cover?
Kildare and the greater Dublin region. Outside that radius, get in touch, and we'll let you know if we can take on the project.
Is there a warranty on the work?
Yes, warranty on the building works, plus manufacturer warranties on doors, windows, roofing and any fittings.