Why Two "Identical" Kits Can Cost Very Different Amounts

Walk around any of the big self-build and garden shows and you will see dozens of log cabin kits that look broadly the same in the brochure. A 4m x 3m cabin with a pitched roof, double doors and two windows. The prices, though, can swing by a thousand pounds or more. That gap rarely comes down to quality alone; it usually comes down to what is and is not included, and to specifications that are buried in the small print rather than shouted about on the sales board.

If you are comparing kits for a garden office, a studio, a guest annexe or an off-grid shelter, the trick is to compare like with like. Below are the specifics that matter most, and the questions worth asking before you hand over a deposit.

Timber Thickness and Wall Construction

The single biggest variable in any log cabin kit is the wall log thickness. Kit cabins are usually described by the nominal width of the machined timber: 28mm, 34mm, 44mm, 58mm, 70mm and beyond. This is measured across the log at its widest point, not the effective solid wall thickness, so a "44mm log" gives you a 44mm wall, not 88mm.

As a rule of thumb in the UK climate:

• 28mm to 34mm suits a summerhouse, shed or occasional-use shelter where you do not need to keep heat in.
• 44mm is the practical minimum for a year-round garden room, and works well if you insulate the floor and roof.
• 58mm and above begins to behave like a proper building and will hold warmth noticeably better, especially with additional internal insulation.

Also check whether the logs are single tongue-and-groove or double tongue-and-groove. Double grooving gives a tighter interlock, less draught and better weather resistance, and it is worth paying for on anything you intend to use in winter. Finally, look at the profile: square or chamfered logs look different but perform similarly; the machining quality matters more than the shape.

Windows and Doors: Where Budget Kits Quietly Cut Corners

Glazing is often the weak point of an otherwise decent kit. A cheap cabin with single-glazed, thin-framed windows will feel cold, suffer condensation and let noise straight through. Check the following before you buy:

• Glazing type. Double-glazed units with argon fill and a low-emissivity coating are the sensible default for anything insulated.
• Frame material. Timber frames are traditional and repairable; uPVC is low maintenance but can look out of place on a log building. Either is fine, but the frame depth and rebate should suit the wall thickness.
• Opening configuration. Tilt-and-turn windows are common on European kits and are excellent, but check they are not so heavy that the log wall struggles to carry them without extra framing.
• Ironmongery. Multi-point locking on doors, and window handles that actually latch properly, are signs of a kit made for real use rather than display.

A useful benchmark: if the kit price looks low but the windows are described only as "glass" or "perspex", the saving is coming out of your comfort, not the supplier's margin.

Fixings, Foundations and What the Kit Actually Contains

This is where hidden costs live. A kit price may cover the timber only, or it may include everything from screws to roof shingles. Ask for a written packing list and check it line by line.

• Roof covering. Is it included? If so, is it felt, shingle, EPDM or metal? Shingles are common and fine, but they need a solid deck underneath.
• Floor. Many kits ship without a floor at all. If included, is it 18mm or 28mm tongue-and-groove, and is it treated?
• Screws, nails, storm braces and trims. These small items add up to well over a hundred pounds if you have to buy them separately, and the correct lengths matter for log movement.
• Treatment. Untreated softwood will grey and can rot. Check whether the timber is pressure-treated, dip-treated or bare.
• Base. Almost no kit includes a foundation. You will need a level, well-drained base — a concrete slab, paving slabs on a compacted sub-base, or ground screws. Ground screws are increasingly popular for garden rooms and off-grid shelters because they avoid digging and can be installed in a day.

Delivery, Access and Assembly Realities

Log cabin kits arrive as a very large, very heavy pallet. Before ordering, measure the narrowest point on the route from the road to your site: gates, side passages, steps and overhanging branches all matter. Some suppliers deliver on a tail-lift lorry and will not move the pallet off the kerb; others will not deliver to a gravel drive. Ask about kerbside versus positioned delivery, and whether a crane or hiab is available at extra cost.

Assembly time is also worth planning properly. A 4m x 3m cabin is realistically a two-person, two-to-three-day job for competent DIYers, plus a day for the base and a day for treatment and roofing. Logs must be allowed to settle, so never over-tighten the roof fixings or cram insulation into the wall joints on day one. Build in a small expansion gap at the top of each wall and keep the storm braces in place for the first year.

Questions to Ask Before You Commit

• Can I see the full specification in writing, including timber thickness, glazing and treatment?
• Exactly what is in the box, and what will I need to buy separately?
• What base does the manufacturer recommend, and does the warranty depend on it?
• What is the lead time, and how is the pallet delivered?
• What does the guarantee actually cover, and for how long?

Get those answers in writing and you will be comparing genuine prices rather than brochure figures — which is the only way to know whether that attractive headline cost is really the cost of your cabin.