Garden Rooms

“This house ain’t big enough for the both of us”


“So much space for activities!” 

Don’t get me wrong, you love them with all your heart. But, jeez we all need our own space right? 

Whether it’s ‘never leaving home children’ or your mother in law coming to stay, a Blackstone Garden Room is the ideal Annex solution for housing the whole family. 


Do not distrub, artist at work. 

Creatives LOVE a Blackstone. Painters, Crafters, Writers and Musicians all need somewhere to go to be amazing at what they do best.

 We know things like; lighting, sound, warmth and practicalities are so important when designing your space and that’s why we do it from scratch, for you. 


A Blackstone that pays for itself!

The working space for you to share your gift. Things like beauty therapies and holistic treatments are fairly traditional working from home businesses, but maybe it’s personal training, a photography studio or a dog grooming stand?
Whatever it is, a Blackstone gives you the opportunity to do it so much better.  


Size plays an important part to the cost structure of a Blackstone. As does, utility. If you’re planning on the building being bigger than 30m2 or running mains water to the building, it will require a Building Warrant and Engineers Certification. This can add a considerable amount to the cost. As you can see below the Annexe pricing is far greater than the the others. 

SMALL £12,000 – £15,000.00

MEDIUM £15,000 – £25,000.00

LARGE £25,000 – £40,000.00

ANNEXE £60,000 – £80,000.00

Here’s and example of the things we cost for.

  • Planning / Building Control 
    (in few cases required)
  • Site Preparation & Basework 
  • The outer body 
  • The inner body 
  • Roofing 
  • Windows
  • Doors
  • Internal Finishing
  • External Finishing
  • Verandah
  • Heating
  • Electrics
  • Decorating

Make Up

Specification is what makes Gillies and Mackay special. We love to get specific. 🙂 

19mm Scandinavian Pine redwood tongue and groove weatherboard. We love our redwood, but there are other options, like Larch and Cedar for those with a bigger budget.  22mm breather cavity with membrane and 9mm OSB bracing. 95mm x 45mm pressure treated framing. 70/100mm Ecottherm Insulation. 12.5mm Plasterboard & 16mm redwood V’d lining.

Framing ranges from 95mm x 45mm to 180mm x 45mm, it depends on the size of the building and whether or not Grant feels the need. It’s the same with the insulation. I like to put 100mm in the roof and floor to cozy the heat in, but depending on your budget you may be happy with just the 70mm. We work the cavity through the roof, like the walls and use a Proctorshield membrane which is specific for roofs.

There’s a few options for the covering. Most opt for either the Steel Box Profile or the Bitumen Shingles. It really comes down to your own preference.

70/100mm Ecotherm Insulation, 19mm tongue and groove redwood flooring and 95mm x 45mm framing. fairly straightforward. We love to use laminate for finishing too. The good stuff – QuickStep.

We use Sadolin Superdec and fine well you know it 😉 we can arrange a decorator to carry out the second coat required within 3 weeks of assembly. If you’re having Larch or Cedar, you can have it with just a primer and let the natural timber do its thing.

Electrics, decorating and finishings, we’ve got you covered. Depending on location, we can arrange to have our electrician visit you and talk through everything you require. A decorator is needed for aimes taping if you opt for plasterboard. If you’re going for V’d lining you may manage the interior yourself or again, we can arrange a decorator to carry out the works for you.

Blackstone?! Tell me more...

Cara Mackay

Questions, answered.

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