House Extensions and Building Services in Ystrad Mynach
From a property extension to a new patio, here is what GTA Builders does across the Caerphilly area.

House Extensions
An extension is often the simplest way to get the kitchen, family room or extra bedroom you need while staying in the home and the street you already like. GTA Builders builds house extensions in Ystrad Mynach and across the Caerphilly area, from the footings up to the finished walls.
The aim is an extension that looks as if it was always there. That means matching the render, pebbledash or brickwork of the original house, and lining up the roof and floor levels with what is already there.
Typical jobs
- Single-storey rear and side extensions
- Two-storey extensions
- Kitchen and family room extensions
- Foundations, blockwork and roofs
- Rendering and plastering to finish
Worth knowing
- In Wales, a single-storey rear extension can reach 4 metres from the back wall under permitted development.
- Building Regulations are separate from planning, and most extensions need them.

Loft and Garage Conversions
If the plot is tight, the room you need may already be there. A loft or garage conversion turns unused space into a proper part of the house, without adding to the footprint.
Whether a loft will work depends on the roof's height and how it is built, and a garage depends on its walls and floor, so the first step is having the space looked at.
Typical jobs
- Loft conversions
- Garage conversions
- Stairs, floors and insulation
- Plastering to finish
Worth knowing
- Both kinds of conversion need Building Regulations approval.
- Some newer estates have conditions on converting a garage, so check your planning history first.

New Builds and Groundworks
Good buildings start below ground. GTA Builders takes on new builds and the groundworks behind them, as well as garages and outbuildings on an existing plot.
The hills around Ystrad Mynach mean sloping sites are common here, so the ground is often the first thing to sort out before the walls go up.
Typical jobs
- New builds
- Foundations and concrete bases
- Garages and outbuildings
- Blockwork and brickwork
Worth knowing
- New homes in Wales need planning permission and Building Regulations approval.
- Sloping sites may need retaining walls, which can be built as part of the same job.

Renovations and Refurbishments
Some properties need more than a coat of paint. GTA Builders refurbishes single rooms and complete houses, stripping back to the structure where it is needed and rebuilding from there.
Taking down an internal wall or reshaping a floor plan can change how a house works without adding a single square metre.
Typical jobs
- Complete property refurbishments
- Internal walls and layout changes
- Ceilings, floors and joinery
- Older houses brought up to date
Worth knowing
- Taking out a wall that carries weight needs a structural design and Building Regulations approval.

Kitchens and Bathrooms
Kitchens and bathrooms get the hardest use of any room in the house, so what is behind the walls matters as much as what is on them. GTA Builders fits both, and that often starts by stripping the room right back.
The photo here is a wet room the firm fitted: new stud walls and pipework first, then boarding, tiling and the fittings. You can follow the same job from start to finish on the About page.
Typical jobs
- Kitchen fitting
- Bathroom fitting
- Wet rooms and walk-in showers
- Wall and floor tiling
Worth knowing
- A new kitchen fits naturally with an extension, so it is worth asking about both together.

Roofing and Carpentry
Every extension needs a roof that ties in properly with the one already there. GTA Builders handles roofing and carpentry as part of a bigger build, or as a job on its own.
That covers the timberwork as well as the covering, so one team is looking after the whole of the roof.
Typical jobs
- Roofs for extensions
- Roof repairs and re-covering
- Structural timberwork
- Stud walls and general carpentry
Worth knowing
- Bats are protected, so any signs of them in a roof need checking before work starts.

Rendering and Plastering
Rendering protects a wall and sets the look of a house, and matching it is often what makes an extension disappear into the original building. Plastering gives inside rooms a flat, sound finish to decorate.
Both are done by GTA Builders on its own extensions and also booked as jobs in their own right, on houses and on garden walls.
Typical jobs
- External rendering
- Garden wall rendering
- Internal plastering
- Patching in around new work
Worth knowing
- Old render has to be sound before anything goes over it, so loose areas are usually taken off first.

Patios, Walls and Landscaping
Plenty of gardens around Ystrad Mynach are on a slope, which makes retaining walls, steps and levelled patios the difference between a garden you look at and one you use. GTA Builders builds all of these, and most of the firm's job photos on this site are garden work.
Garden rooms and general landscaping are covered too, so an extension and the garden around it can be finished as one job.
Typical jobs
- Sandstone and slabbed patios
- Retaining walls and garden steps
- Block paving and gravel paths
- Artificial lawns
- Garden rooms
Worth knowing
- A garden room may not need planning permission, depending on its size and where it sits on the plot.
Planning an Extension in Ystrad Mynach?
Talk it through with GTA Builders and get a free quote.