County Antrim · Northern Ireland

Building regulations for two-storey extensions in County Antrim

Planning an extension in County Antrim? This is how our building regulations service works, with the Northern Ireland rules and typical fees.

County Antrim at a glance

Nation
Northern Ireland
Price region
Northern Ireland
Postcode areas
BT
Towns covered
15 listed below, plus surrounding villages
Site visits
Free, no obligation

What a building regulations application involves

This service suits every two-storey extension, because each one needs building regulations approval wherever you live in the UK. You get technical drawings and a specification coordinated with the structural engineer, a full plans application, site inspections arranged at each stage, and the completion certificate you will need when you sell. We manage the process, and the work is carried out by vetted teams working under S&K.

Across County Antrim we cover Belfast (BT1), Lisburn (BT10), Newtownabbey (BT36), Castlereagh (BT4), Carrickfergus (BT38) and Ballymena (BT42), plus the smaller places around them.

Fees

Technical drawings and specification are a guide of £1,500–£4,000. The council's building control fee depends on the value of the work; we confirm every fee in writing before the design stage starts.

Rules in Northern Ireland

In Northern Ireland, building control approval comes from the local council under the Building Regulations (Northern Ireland), with the Technical Booklets setting out how to comply. A full plans application is usual for two-storey extensions, and the council inspects the work and issues a completion certificate.

Approval in Northern Ireland: Planning application for works to a house: £347. Councils aim to decide local applications within an average of 15 weeks; many take longer.

Building control: Building control approval from the local council under the Building Regulations (Northern Ireland), using the Technical Booklets.

There is no Party Wall Act in Northern Ireland. Shared walls and boundaries are a matter of title and common law, so we agree access and record conditions with neighbours before work starts.

Getting the design right

Full plans and inspections

Full plans approval checks the design before work starts, which we recommend for two-storey extensions. Building control then inspects key stages, such as foundations, damp-proofing, drainage and insulation, before issuing the completion certificate.

How we work in County Antrim

  1. Measure and listen

    A visit to County Antrim to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.

  2. Choose the approval route

    Some designs fit permitted development, most need a householder application. We decide which applies in Northern Ireland before drawing in detail.

  3. Technical design

    We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.

  4. On site

    One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.

Towns we cover in County Antrim

Building regulations for two-storey extensions in County Antrim: questions

Do I need building regulations if I have planning permission?

Yes. Planning permission and building regulations are separate. Planning covers what the extension looks like and how it affects neighbours; building regulations cover how it is built and whether it is safe, warm and healthy. A two-storey extension needs both, unless permitted development replaces the planning part.

What is a build-over agreement?

A build-over agreement is permission from your water company to build over or near a public sewer. Many rear extensions sit near shared drains, and the water company will want access protected and the pipe checked. We check sewer records early so the agreement does not delay the start.

Neighbouring areas

All extension services in County Antrim · About building regulations for two-storey extensions

Ready to see what a second storey could do for your home?

Book a free site visit. We'll look at your house, talk through options and explain the approvals you'd need, then price the design stage in writing.

CallGuide price