The plastering needs of a new build extension or conversion differ considerably from replastering an existing room. Understanding the difference helps you plan your project and budget accurately.
New Build Plastering
In a new build or extension, walls are typically constructed from blockwork or timber frame. The plasterer will apply:
- A base coat (browning or bonding) to even out the surface on blockwork
- A finish skim coat to achieve the final smooth surface
- On timber frame: fix plasterboard, tape joints, then skim
New build plastering is generally faster per m² than renovation work because there is no existing material to remove, walls are regular, and access is unobstructed.
Renovation Plastering
In renovation work, old plaster may need to be hacked off first. Walls are often irregular with patches of different ages. There may be moisture issues, old lime plaster that needs special treatment, or features like original cornicing that require care.
Renovation plastering typically takes longer and costs more per m² than new build work due to:
- Preparation and hacking off time
- Irregular surfaces needing more material
- Restricted access and working around furniture and fittings
- Need to match existing finishes
Timing Within Your Project
| Stage | New build | Renovation |
|---|---|---|
| First fix complete? | Yes — plaster after electrics/plumbing | Yes — fix damp first |
| Plaster stage | Before second fix and decoration | After all structural work done |
| Drying time | 4–6 weeks before decoration | 4–8 weeks (old buildings) |
| Decoration | Mist coat first | Mist coat first |
Get Quotes for Your Plastering Project
Whether new build or renovation, compare up to 3 free quotes from local plasterers who can advise on the right approach.