An extension is one of the best ways to get more space without moving house. One of the first decisions is whether to go out on one level or build up to two storeys. Both can transform a home, but they suit different needs, budgets and plots.
Single-storey extensions
Single-storey extensions are the most popular choice for kitchens, dining and family rooms. They open up the back of the house to the garden and work well with roof lights, lantern roofs and large glazed doors.
- Simpler design and structure
- Often less complicated from a planning point of view, and some may fall within permitted development
- Less disruption to the upstairs of the house during the build
The trade-off is that they use more of your garden for the space you gain.
Two-storey extensions
A two-storey extension adds space on both floors – for example, a bigger kitchen downstairs with an extra bedroom or ensuite above.
- More floor area for a similar footprint
- Better value per square metre, because the foundations and roof are shared across two floors
- Can add significant value by increasing the number of bedrooms
They usually need planning permission, involve more structural work where they join the existing house, and are closer to neighbours at first-floor level, so design matters.
Things to consider
What do you actually need?
Start with how you live. If the problem is a cramped kitchen, a single storey may be enough. If the family is outgrowing the bedrooms, going up makes more sense.
Your plot and neighbours
Garden size, boundaries, overlooking and light all influence what is possible. A good designer will show you the options early.
Ground conditions and foundations
A two-storey extension puts more load on the ground. Foundations may need to be deeper, particularly near trees or drains.
Future plans
If you think you may want to build up later, designing the foundations for a second storey now can save cost down the line.
Get expert advice
SC Developments build extensions of all sizes across Northern Ireland, from compact kitchen extensions to large two-storey additions. Take a look at our home extensions page, or contact us to discuss your plans.
