Extension plans and drawings across Castlereagh
For Castlereagh homeowners we handle extension plans and drawings, with fees agreed in writing before any work starts.
- Guide price in CastlereaghFrom £1,000 inc VAT
- PlanningWe find the right route for you
- Timescale2–6 weeks for drawings
- Postcode districtsBT1, BT2, BT4, BT5, BT6
Design and approval fees for Castlereagh
These are guide fees for Castlereagh, adjusted for Northern Ireland (×0.86) and including VAT. Council application and inspection fees are paid separately.
| Option | What it covers | Guide price |
|---|---|---|
| Essential | Measured survey and planning drawings | £1,000 – £1,900 |
| Standard | Planning drawings plus building regulations drawings | £1,850 – £3,300 |
| Premium | Full pack with structural calculations and 3D visuals | £2,900 – £4,750 |
Try the guide-price tool to see a range for your own size and finish.
Do I need planning permission in Castlereagh?
In Northern Ireland we check the permitted development limits for your house type and, where needed, apply to your council for planning permission, then submit full plans or a building notice to council building control.
Homes in conservation areas, areas of townscape character and listed buildings have tighter rules, so we always check the property's status and planning history before design starts.
Building close to a public sewer needs the agreement of NI Water, which we check during design.
Northern Ireland has no Party Wall Act. Where work is on or close to a shared boundary, we agree access and protection with your neighbour in writing before work starts.
Applications are decided by your council, which handles local planning in Northern Ireland.
Who this service is for
- Projects that need a planning application or other approval
- Homeowners at the very start of a project
- Anyone who wants fixed designs before getting build prices
Extensions in and around Castlereagh
Across BT1, BT2, BT4, BT5, BT6, BT7, we can visit, measure and advise. The same team covers Belfast (2 miles), Newtownabbey (6 miles), Lisburn (7 miles), Carrickfergus (10 miles), all within easy reach.
Northern Ireland's housing ranges from city terraces to large numbers of detached houses and bungalows on rural plots, many in render, where single-storey extensions fit easily.
What happens next
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Common questions in Castlereagh
Do you cover all of Castlereagh?
Yes. We cover Castlereagh and the surrounding parts of County Antrim. Site visits are free and there is no obligation.
Who do I contract with in Castlereagh?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Castlereagh, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do I need an architect?
Not necessarily. For most extensions an experienced designer or architectural technologist is enough. For listed buildings or complex sites an architect’s input can help.
How much do extension plans cost?
Our design packs range from about £1,000 to £4,750 including VAT, from planning drawings only to a full pack with building regulations drawings, structural calculations and 3D views. Council fees are separate.
Book a free site visit in Castlereagh
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.