Site Preparation
Foundation & Groundwork
Every VeltHaven building needs a level, prepared base. Here's what we handle, what you arrange, and how to make your site installation-ready — with or without our managed groundwork service. See our Delivery & Installation terms.
What's in the build price
Included as standard
Every VeltHaven building price includes VAT, delivery to your address and full professional installation. There are no hidden charges on standard sites.
Included in every build
- VAT, delivery to your address
- Professional installation by our team
- Building anchoring to your prepared base
- Doors, windows, guttering fitted
- Part P electrical certification (if you add electrics)
- Delivery date confirmed once deposit paid
Not included (quoted separately)
- The prepared, level base or concrete slab
- Excavation, levelling and drainage
- Non-standard site access or long electrical runs
- Shower or plumbing connections (sauna's optional shower)
Site extras are quoted from your three site photos before manufacture begins. You can cancel for a full refund any time before you pay your balance.
Base types
Ground screws or concrete slab?
Both work. Ground screws are our preferred method — faster to install, no curing time and no concrete lorry in your garden.
Preferred method
Ground screws
Helical steel screws driven into the ground to create a level, load-bearing platform. No digging, no concrete, no waiting for anything to cure. Works on slopes and uneven ground. Fully reversible — removed without trace if you ever move the building.
- Installed in a day
- Works on slopes
- No concrete or curing time
- Reversible and reusable
Traditional method
Concrete slab
A reinforced concrete base — the conventional choice and sometimes required on very soft or waterlogged ground. Needs at least five to seven days' curing time before installation can begin. If you plan to add our Showroom Finish resin floor later, the slab is the correct foundation for it.
- Suitable for all ground types
- Required for Showroom Finish
- Add 5–7 days curing time
- Permanent — plan your layout first
What a base looks like
Base types we prepare
These are the prepared bases our buildings sit on, beyond the ground screws above. We advise the right one for your ground, building and budget from your site photos.
Concrete slab
Best for: most ground types, heavy use, and any building with our Showroom Finish resin floor.
How it works: a reinforced, dead-level concrete pad sized to the building, laid over a compacted sub-base.
Trade-off: needs 5–7 days to cure before installation; permanent, so plan the position first.
Paving or slabs
Best for: a tidy, attractive base on firm, well-drained ground.
How it works: a compacted sub-base of hardcore or sand topped with paving laid flat and level.
Trade-off: more groundwork than blocks, and only as stable as the sub-base and drainage beneath it.
Concrete pads / blocks
Best for: smaller buildings and the quickest, lowest-cost set-up on firm ground.
How it works: precast blocks on a compacted base give point support under the corners and main load points.
Trade-off: the least rigid option — the ground must be firm and evenly compacted to avoid settling.
Strip footing
Best for: larger or heavier garages, and softer ground that needs more support.
How it works: concrete poured into perimeter trenches carries the walls down onto firmer subsoil.
Trade-off: the most groundwork of the four, and permanent like a slab.
Get these right
What matters on any base
Whichever base you choose, three things decide whether the building lasts and looks right. We confirm the exact dimensions and a level tolerance before you prepare anything.
Dead level
The single most important thing. An out-of-level base shows up in the doors and the roofline, and stops sliding doors running true. The base must be flat and square to the dimensions we give you.
Drainage & fall
Choose ground that does not pond after rain. A slight fall away from the building, and a channel or soakaway where needed, keeps surface water from sitting against the structure.
Damp-proofing
On a concrete slab, a damp-proof membrane under the pour keeps the floor dry. It is essential for an insulated garden room and for the resin Showroom Finish floor.
Choosing the spot: a firm, level area with clear vehicle and pedestrian access, away from large tree roots, overhead cables and underground services. Unsure? Send your three site photos and we will advise the right base before you commit.
Optional service
Let us manage it
Rather not organise a groundworks contractor yourself? We can coordinate site preparation as part of your build — the base is ready before our installation team arrives, and you deal with one company throughout.
Managed groundwork is priced individually after we've reviewed your site photos — it depends on access, soil conditions, the size of your building and whether ground screws or concrete is the right choice. We quote before you commit.
Ask about managed groundworkPrice guide
Typical groundwork costs
These are typical contractor ranges for a standard UK site — level ground, normal access, no unusual drainage. Non-standard sites are quoted individually from your photos.
Steel Garages (concrete slab)
| Garage 24 (4×6 m) | Garage 30 (5×6 m) | Garage 36 (6×6 m) |
|---|---|---|
| £4,500 – £7,500 | £5,500 – £8,500 | £6,500 – £9,500 |
Insulated Garages
Same footprint as the Steel Garages (4×6, 5×6, 6×6 m). A concrete slab is standard, though ground screws are an option on well-drained sites. Ranges broadly similar to the Steel Garages above.
Garden Rooms & Spas
Quoted individually — footprint, access and finish requirements vary more widely. We give you a groundwork estimate alongside your build quote, after reviewing your site photos.
Ranges are for a standard UK contractor on a normal access site. Costs vary with ground conditions, excavation depth, and local labour rates. VeltHaven-managed groundwork is quoted separately and confirmed before manufacture begins.
Site checklist
What makes a standard site?
Standard sites are included in the build price. Anything non-standard is quoted and agreed from your site photos before manufacture — you decide whether to proceed.
Standard — no extra charge
- Prepared, level base of the correct size
- Normal vehicle and pedestrian access
- Electrical connection within ~15 m of the building
- Spare way on the existing consumer unit
- No trees, roots or overhead cables in the work area
Non-standard — quoted separately
- Restricted access (narrow gate, steps, steep slope)
- Electrical run longer than ~15 m, or trenching required
- Fuse-board upgrade needed
- Waterlogged, clay, or rock ground
- Tree roots or underground services nearby
Non-standard extras are always quoted and confirmed before manufacture. Full refund before your balance is paid.
The process
From site to installed
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Configure & deposit
Choose your building in the configurator and pay your deposit online. Your order is confirmed.
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Send your site photos
Three photos of the site let us plan delivery and confirm your installation date. Non-standard extras are quoted at this stage.
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Prepare your base
Your groundworks contractor (or our managed service) prepares the base. Buildings are typically ready to install within 2–6 weeks of your order.
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Installation day
Our team delivers and installs your building — doors, windows and guttering — in one to two days for a garage (a garden room a little longer; a sauna in a day), weather permitting. Electrical and other extras follow on a separate scheduled visit.
Common questions
Groundwork FAQ
Do I have to use VeltHaven for groundwork?
No. Many customers organise their own local groundworks contractor and simply ensure the base is level and the correct size before our installation date. We provide the exact dimensions once your order is confirmed. You can also ask us to manage it as an add-on — whichever is easier for you.
Can I lay a base before ordering?
Yes — if you already have a concrete slab of the right size and it's level, we'll build straight onto it. Confirm the dimensions with us before you pour so nothing needs to be redone.
Why are ground screws preferred over concrete?
Ground screws are installed in hours, require no concrete lorry, and leave no permanent change to your garden if you ever want to relocate the building. They also work on gentle slopes without the levelling excavation a slab requires. On very soft or waterlogged ground, a reinforced concrete slab is the better choice — we advise after seeing your site photos.
What if my site turns out to be non-standard?
Non-standard conditions are quoted from your three site photos after you place your deposit. We tell you the extra cost before manufacture begins. If you decide not to proceed, you get a full refund any time before you pay your balance — no questions asked.
How long does groundwork take?
Ground-screw installation typically takes half a day to a full day. A concrete slab takes one to two days to lay, then five to seven days to cure before the building can go on top. We factor this into your delivery schedule — just let us know your timeline when you order.
Does groundwork affect planning permission?
The base itself (ground screws or a shallow concrete slab flush with the ground) does not normally require separate planning permission in England and Wales. The building above it may require a permitted development check or a full application depending on size and siting — the configurator provides guidance on this for each product. If you are unsure, consult your local planning authority.
The VeltHaven Groundwork Guide
What base type suits your site, how to brief a contractor, questions to ask — and how managed groundwork works if you want one less thing to arrange. Free, by email.
Ready to move forward?
Plan your build
Configure your building and get a live price in minutes. Or talk to us about your site and we can guide you through the groundwork options.