Wollondilly Shire Council
Private building certifier in Tahmoor
Tahmoor sits almost entirely within a mine subsidence district, with older streets near the station and newer estates at the edges. CertifiBuild certifies homes, extensions, granny flats and pools across both settings.
NSW 2573
Class 1 homes and Class 10 structures
Local rules
Tahmoor: station town, new edges and subsidence
Two kinds of growth
Council's centre study sees Tahmoor as a town that serves locals and nearby villages for everyday shopping. It flags room for more housing and activity close to the station, while low density housing spreads at the town's edges. A backyard infill project and a home on a freshly subdivided lot start from quite different assumptions. The 2021 figures put detached homes at 90.8% of those occupied. Semis or townhouses were 7.7%, and flats 0.8%.
Release-area provisions
Wollondilly's development control plan (DCP) has growth provisions for identified land across Picton, Tahmoor and Thirlmere. They cover how release land is staged, how people move through it, servicing and stormwater. Those rules cover the mapped land alone, and not each older property in the town. Check your current zone and subdivision approval first.
Mine subsidence
Official maps show nearly the whole Wollondilly section of Tahmoor in the Bargo subsidence district, with a narrow strip in the Wilton one. That measures land area, not houses. Unless an exemption applies, Subsidence Advisory NSW normally has to approve building or subdividing. Pin down the guideline for your property before any structural design.
Typical work
Common projects and how they get approved
What owners build here
Most homes are detached, but infill and attached homes also feature. Typical Class 1 and 10 work includes:
- New houses across the release lots, sited to the approved envelope and drainage plan.
- Extensions and rebuilds on established lots, fitted around access and the house already there.
- Granny flats, assessed as a separate use from dual occupancies with their own standards.
- Dual occupancies near the station, where current zoning allows.
- Pools, garages and alfrescos, with footings matched to the subsidence guideline.
Apartment buildings are a tiny part of local housing and fall outside the Class 1 and 10 work we certify.
How approval usually works
Get the subsidence guideline for your lot before engineering is finalised. A slab detail used on another Tahmoor house may not suit yours. Then check if the mapped release land takes in your lot. If it does, staging and services provisions apply; if not, start with the dwelling and lot category in council's residential controls. Planning two homes on a single lot? Settle early on whether it is a granny flat, a dual occupancy or multi-unit housing, since the rules differ for each. A CDC, a fast-track approval under state rules, may suit if the design and land qualify; otherwise a DA, then a construction certificate. CertifiBuild lines up the subsidence, release-area and use questions at the start, so footings and layouts are not redrawn later.
Our services
From approval to sign-off.
One certifier for your whole Tahmoor job, from the first plan check to the occupation certificate.
Local questions
Questions we hear about this suburb.
No two lots in Tahmoor are the same. Give us your address and we will check every map that affects it.
See the council pageCould I put two homes on my Tahmoor block?
Possibly, if your zone and the standards allow a dual occupancy. Council’s centre study flags room for more homes around Tahmoor station, yet that study approves nothing on any specific lot. First decide exactly what you want, because a granny flat, a dual occupancy and multi-unit housing are different uses with different rules. Then review the layout, driveway access, services and the mine subsidence guideline for your property. Once those are clear, you can choose between a complying development certificate (CDC) and a development application (DA).
Will my Tahmoor house use the same footings as my neighbour’s?
Not necessarily. Nearly all of Tahmoor sits within the Bargo mine subsidence district, with a narrow strip in the Wilton district, but the structural requirements depend on your property’s own guideline and the work you propose. Unless an exemption applies, Subsidence Advisory NSW usually needs to approve building work. A slab or footing detail used next door may not suit your lot. Get your property’s guideline before your engineer finalises the design, so footings are not redrawn later.
Do estate rules still apply to my pool in a newer Tahmoor street?
They can. Council’s growth provisions for Picton, Tahmoor and Thirlmere apply to the mapped release land, covering staging, movement, services and stormwater. Where your block falls inside that area, or its subdivision approval has conditions that still run, your pool or alfresco plans may be affected. Check your subdivision approval, title and drainage plan before choosing a spot. Keep the approved stormwater layout, driveway access and remaining yard space in mind, and match pool footings to your mine subsidence guideline.
Building in this suburb?
Send us the address first.
We check the local maps for your lot, confirm the approval path and quote in writing.