New homes, extensions and conversions across Cornwall, built by one St Austell team with every trade in house since 2008.

We provide building, carpentry and general property maintenance across the whole of Cornwall, for domestic and commercial clients. Every project starts with a free, no obligation survey and quotation.

4.9 from 15 Google reviewsUnit 5, Tregrehan Mills, St Austell
Finished house with a dark-clad first floor, a slate-paved courtyard and raised planters
Trading since 2008
Plumbing, electrics, carpentry and gas in house
We source all the materials
All our work is guaranteed

What we build

We're a team of experienced people with skills across all areas of construction, so one call covers the whole job. Domestic & commercial projects, large or small, are all welcome, whether that's general repairs or complete new-build project management.

White rendered new-build house with a slate roof, a worker on a ladder finishing the exterior

New builds

Complete project management for new-build houses from start to finish, with guidance every step of the way. From groundworks through to decorating, we have you covered.

  • New-build houses, managed start to finish
  • Self-build assistance, as much or as little as you need
  • All trades supplied: electrics, plumbing, carpentry, gas and more

Warranties can also be arranged.

Finished single-storey extension with a Cornish stone base and white windows

Extensions, conversions and renovations

More room without moving house. We build extensions and conversions for many types of property, keeping disruption to your day-to-day life as low as we can, and we can turn older properties into homes for modern families while keeping their classic features.

  • Single Storey and Two Storey extensions
  • Side and rear extensions
  • Wrap around extensions
  • Loft Conversions
  • Barn Conversions
  • Garage Conversions
New white kitchen with a pale stone worktop, black extractor and oak-effect floor

Kitchens and bathrooms

A speedy, reliable kitchen and bathroom service at an affordable price, from small walk-in showers to large, luxurious bathrooms. You won't need to book other contractors: we do the plumbing, carpentry, electrics and general building in house, with materials from local merchants we've used for many years.

  • Complete re-fits, make-overs and refurbishments
  • Additional wet rooms, shower rooms or en-suites
  • Floor & wall tiling
  • All electrical and plumbing work carried out
  • Integrated appliances fitted
  • New shower units
White clad house in Polruan with large aluminium windows and glass balconies

Windows and doors

We supply and fit, whether you need a single window replacement or want to upgrade the whole of your property. We have great access to a wide range of products, so matching your existing look or finding a new style to complement your home is easy.

  • uPVC windows and doors, double and triple-glazed
  • Composite front doors
  • Timber and aluminium windows
  • French doors, bi-fold doors and pivot windows
Large-format grey patio being laid in a walled garden, a worker setting the slabs

Property maintenance, driveways and patios

Services that enhance your property visually as well as functionally, with complete project management. We carefully plan all works with you before buying the materials, and we've installed drives on flat, level ground as well as steep inclines.

  • Driveways in block paving, Tarmac, gravel and concrete
  • Patios in a wide choice of paving, colour and texture
  • Fascias, guttering and cladding: repairs and replacements
  • General repairs for homeowners

Carpentry, in house

Carpentry is one of the trades we keep in house, so it's done by our own team alongside the building work around it.

Oak and white staircase over an oak floor
Floating oak stairs with a glass balustrade
Oak front door with glazed side panels and a sea view, Polruan
Larch-clad porch canopy over sandstone paving

Self-build help, as much or as little as you want

Self builds can be a lot to take on. Juggling several trades in tandem with unpredictable weather and the changing seasons can be extremely challenging, and managing a site is hard if you don't have much experience in the industry. Whether you'd like complete assistance or simply a guiding hand in overseeing your project, we can help with:

  1. 1.Interpreting architectural & engineering drawings
  2. 2.Project scheduling
  3. 3.Material acquisition & storage
  4. 4.Building regulations
  5. 5.Delivery & implementation
  6. 6.Site safety

From groundworks through to decorating, we have people for every trade: electrics, plumbing, carpentry, gas and more. We'll happily meet you, outline what's involved and give you a free, no obligation quotation.

Timber-frame new build inside scaffolding, fields behind
Our crew levelling a new foundation slab in open countryside
Blockwork extension with the roof trusses going on
Extension framing in progress, walls being boarded

What our customers say

4.9 from 15 reviews on Google

“MAC Construction have just finished the second job for us in the last few months.

First, they changed a rather grotty back of our garage into a beautiful utility space, with fitted kitchen, worktops, plastering, spotlights and new electrics and tiled floor. All work was completed as promised, earlier than we hoped and to a brilliant standard.

Most recently they converted the end of our bedroom into a new ensuite, fitted 3 new radiators, split a large window into two smaller ones and completed all plastering, plumbing and electrics to deliver a fantastic new space.

Ben did a fabulous job with brilliant communication and delivery by Adam @ Mac.

If you are planning any building work or home improvements you can't go wrong with MAC!”

Adam Read, Google review, November 2024
“MAC Construction built an extension for me a couple of years ago and have recently done some addition roofing work. Excellent high quality workmanship and fair prices. Both jobs were on time and on budget.”
Geoff Dennis, Google review, March 2025
“Well organised great team of builders . Everyone was helpful. They worked to a tight deadline around my needs and constraints. Would highly recommend the team”
Amanda, Google review, March 2026
“Could not have been happier with their work, after searching for good tradespeople with it all being pot luck what type of service you will get. just use Macs, there is no comparison. save your time and energy, they are professional, courteous and incredible at what they do. I will definitely be using them again.”
Tom, Google review, December 2024

Steve Cooke
Google review, August 2021

“Further to the recent installation of a completely new kitchen, I am just leaving this review to say that in every aspect, the complete service provided by MAC Construction (St Austell), from not only the members of the installation team but that from the Office Staff as well, was unbeatable. The whole team worked together effectively, is a truly professional unit and I would not hesitate in recommending this Company as one that (in my opinion), will almost certainly provide excellent value in terms of the standard and quality of workmanship, support from all members of the overall team as well as being excellent value for money. Based on the work they completed in installing the kitchen, for me, I had no hesitation in using the same Company to complete other tasks because I knew after what had already been completed, that whatever they do is of the highest quality.”
The MAC Construction team lined up in front of our vans at the yard

One team, every trade

MAC Construction has been trading since 2008. Our purpose is simple: reliable, trustworthy construction for people in and around Cornwall. The team is made up of many skilled people who come together on every project, large or small, so you won't need to book other contractors or rely on us booking subcontractors.

As part of the service we'll source all the materials and products a project needs, then install them to an exceptionally high standard. Our work is competitively priced and comes with a guarantee for your complete peace of mind.

  • Friendly Approachable Staff
  • Experienced, And Qualified Operatives
  • Free Advice, Quotations And Surveys
  • Guaranteed Work
  • Updates, And Continued Communication Throughout The Project

Around Cornwall

Houses, extensions, gardens and groundwork from Polruan and Gorran Haven to Tywardreath, Hewas Water and the Eden Project.

White clad house with large aluminium windows and glass balconies, Polruan
Polruan
Single-storey extension with roof windows and wide glazing onto the garden, Gorran Haven
Gorran Haven
Pale shaker-style kitchen with a pendant light, Hewas Water
Hewas Water
Self-build house in stone and render with dark windows
Glass balcony and white cladding looking out to sea, Polruan
Polruan
Rendered house with a slate roof and a roof window, Tywardreath
Tywardreath
Clad house with new windows above the sea, Polruan
Polruan
Groundwork with a digger and our van in front of the Eden Project biomes, Eden Project
Eden Project
Dark clad garden room with French doors on a stone base
Cottage living room with a wood burner under a timber lintel
Rendered raised beds, lawn and slate paving around an olive tree
Stone and render house under construction with a glass balcony
Cornish stone house with a new grey-framed conservatory
Fitters installing large sliding doors on a new extension
New garden with decking, lawn and porcelain paving
New decked terrace with timber fencing outside a house

Where we work

We're based at Tregrehan Mills, just outside St Austell, and we cover the whole of Cornwall, including:

  • St Austell
  • Truro
  • Newquay
  • Bodmin
  • Perranporth

If you don't see your area, please get in touch.

Tell us about your project

We'd like to hear about it. We offer a free, no obligation survey and quotation on all projects, and plenty of advice to help you get the best outcome.

Find us
Unit 5, Tregrehan Workshops, Tregrehan Mills, Saint Austell PL25 3TQ
Office hours
Mon-Fri 9:00-16:30
Sat and Sun closed

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Call 01726 64827