How we chose
We started from the sixteen garage conversion firms Google Maps shows across Telford. Scheme memberships were sourced from the TrustMark and Federation of Master Builders registers, each firm's own website and platforms such as Which? Trusted Traders [6] [7]. Each business must first meet our basic checks: it is who it says it is, it is trading today and can be reached, and anything it must hold by law is in place. Seven firms met all three. What customers say counts most toward the score, then proof of competence, then whether the firm has traded two years or more and whether its cover is stated, then pricing clarity and website detail. All evidence is dated early September 2026.
How to hire
Start by matching the firm to the shape of your job. A dedicated converter suits a straightforward room-in-the-garage, an established builder suits a conversion wrapped inside an extension or renovation, and a timber firm suits oak-framed work or a joinery-led finish. A detached garage needs power, heat and sometimes drainage run from the house, so ask whoever you call how they handle services, and whether any of that work is subcontracted, before you go further.
Planning permission is usually the easy part: internal work that does not enlarge the building normally needs none, though a separate home, a listed building or a street with restricted rights is different [1]. Telford and Wrekin runs pre-application advice for borderline cases, and a lawful development certificate settles the question in writing [1]. Ask the council before anyone starts, since new estates around Telford often carry conditions that remove the usual rights.
Building control is the part you must not skip. Telford and Wrekin says a garage conversion commonly counts as permitted development yet always needs building control approval where a room people will live in is created [3]. Your builder can apply with full plans for certainty or by building notice where the work is minor [4]. Either way, keep the completion certificate with your deeds and hold back final payment until it is issued [4].
Check competence on the registers before you book. Search the TrustMark site for the business name and check any licence number yourself rather than taking a logo at face value [6]. For builders, the Federation of Master Builders runs its own check-a-member page [7]. New wiring must be certified by a competent person, so confirm the electrician on the NICEIC register [9], and any boiler or gas work belongs to a Gas Safe registered engineer [10].
Get two or three itemised written quotes on the same room-by-room scope so you compare like with like [8]. Each quote should split labour, materials and VAT, name the start and finish dates, say who arranges building control and what certificates arrive at the end, and tie stage payments to finished work [8]. Where a price looks vague, ask which trades stay in-house and which are subcontracted, and get the answer added to the quote.
At handover, collect the completion certificate for the building control sign-off, the electrical certificate for any new wiring, and any written guarantee the firm offers on its own terms. Photograph each stage as the work progresses and keep every certificate with your house deeds: a buyer or remortgage lender will ask for them. If anything falls short, raise it against the written quote first, and keep a dated photo record of every snag until it is put right, with Citizens Advice as backup [8].
Pricing
As of autumn 2026, a national cost guide updated that May puts a typical single garage conversion at ten to twenty thousand pounds for a standard integral or attached garage, while detached and double garages cost more [5]. Only the top firm in this round publishes its own figure, so treat every other number you see as a starting point. Send each bidder the same scope and ask for the itemised fixed quote this guide prices against.
What moves the price is the shell you start from and the room you want at the end. Floor build-up and damp-proofing, wall and roof insulation, extending the heating, new windows and the door infill, and any plumbing or drainage for a shower room or kitchen all add cost [5]. A detached garage usually costs most, since power, heat and water must be run from the house [5]. Finer finishes, underfloor heating and bespoke joinery sit on top of all that, and keeping one parking space can matter to a future buyer.
Ask every bidder whether VAT is included or added, since published ranges can read either way, and check what the building control fee adds [5]. A quote without the letters VAT on it is unfinished business. Get the full scope, the stage payments, the start date and the certificates you will receive written into the quote before anyone lifts a tool [8].
Red flags
Starts work with no mention of building control approval or who arranges it [2].
Quotes a full conversion without visiting or asking for photos, measurements and drainage details.
Gives one fixed figure with no breakdown of labour, materials and VAT [8].
Asks for full payment in cash before starting, with no written scope or stage terms [8].
Cannot name a TrustMark licence or Federation membership you can check yourself on the scheme register [6] [7].
Leaves new wiring or heating with no competent-person certificate behind it [9].
Clears the garage with no waste carrier number you can check on the public register [11].
The bottom line
For most Telford homes, start with Midland Garage Conversions: a dedicated converter with published prices and TrustMark backing listed on the register. Its review base is small, so read the published reviews alongside the scorecard and ask for recent local examples before you agree anything.
Match the firm to the job otherwise: Randle for extensions with renewables in the same contract, Rubik for a conversion inside a wider retrofit, Salopwood or Salop Timberworks for timber-led work, and R and R where one firm should run the whole project. Then get a couple of itemised quotes on the same written scope and check the building control position before anyone starts.
Corrections and business responses
Tell us what needs checking, or ask to claim a listing and reply to an assessment.