Fit-Out Cost Estimator

Railway arch fit-out costs range from £45/sqft for basic storage conversion to £175+/sqft for specialist uses like breweries and commercial kitchens. The variation comes from three main factors:

• Shell condition: A bare arch needs waterproofing, insulation, flooring, and all M&E services from scratch. A previously fitted-out arch may only need adaptation.
• Sector requirements: A brewery needs three-phase power, floor drainage, and extraction. A creative studio mainly needs good lighting and basic heating.
• Arch characteristics: Victorian brickwork requires specialist waterproofing. Curved walls complicate standard insulation. Listed building status may restrict materials and methods.

1. Waterproofing (£15–£30/sqft)

The single most important item for any arch fit-out. Railway arches are prone to damp from water ingress through 150-year-old brickwork. Options range from cementitious tanking to cavity drain membranes. The Arch Company explicitly excludes liability for water ingress.

2. Insulation (£10–£25/sqft)

Arches have no inherent thermal insulation. Spray foam, rigid board, or mineral wool against a stud wall are common approaches. The curved walls make standard solutions more complex and expensive.

3. Electrical & Plumbing (£20–£48/sqft combined)

Many arches have only a single-phase supply. Upgrading to three-phase costs £3,000–£8,000. Water supply, drainage, and waste connections are often limited and need extending.

Common Mistakes

• Underestimating waterproofing — the cheapest option often fails within 2–3 years
• Forgetting planning permission for extraction, signage, or change of use
• Not commissioning an asbestos survey (required by law, costs £300–£800)
• Bolting fit-out to the arch structure — most landlords require freestanding installations
• No contingency budget — always add 15–20% for unexpected issues