The Southlands Observatory

An updated version of our Summer Observatory, featuring the latest materials and lighting.

Our Summer Observatory has been one of our most popular designs ever since we built it for Neil and Sue Worthington back in 2018. Now, eight years later, we’ve had the pleasure of updating the design for a new customer based in the South of England.

The observatory measures approx 7×7′, with an identically-sized 7×7′ warm room that doubles as a garden office. Thanks to a sleek anthracite UPVC door and window, coupled with “Rich Espresso” cladding, its smart exterior gives a hint of the technology contained inside.

Internally, the observatory is finished in marine ply, painted black in the observatory itself and white in the warm room, providing a light and bright work environment. Bright downlights provide excellent lighting for work and hobby tasks in the warm room, while a statement square LED channel gives an amazing even red light for astronomy tasks.

The level of professionalism and efficiency in the build was outstanding

CHRIS POULTER
An updated version of our Summer Observatory, the Southlands Observatory makes the most of its footprint, providing a large observatory on even the smallest site.

EPDM FLAT ROOF

Our ‘flat’ roof (it has a slight angle to allow rainwater to drain off) is covered with a single-piece EPDM rubber membrane. The lack of any joints means there’s no leaks, and the tough rubber membrane resists damage by impact or weathering, resulting in an expected 50-year lifespan. Where appropriate, we’ll fit a gutter on the low side to channel water away safely to the ground.

Built-In LED Lighting

Our latest observatories feature striking red and white LED light built into the walls! The separately-switched red and white strips are driven by very high quality power supplies and use a Varilight VPro dimmer, allowing them to be dimmed to almost nothing – so you can have as much or as little light as you wish. Building them into the walls means no bulky fittings or obstructions, maximising the space in your observatory.

painted interior

Available as an option, our fully painted interior maximises your experience. We will paint the observatory matt black internally to minimise reflections, and the warm room can be painted in your choice of colour to enhance comfort in daytime use. If you opt for the painted interior, we upgrade the internal wall lining from 11mm OSB to 12mm moisture-resistant MDF.

Overall Size (mm):4000 (L) x 2200 (W) x 2475 (H)
 Observatory Size (Internal, mm):1972 (L) x 1839 (W) x 1650 (H)
 Warm Room Size (Internal, mm):1972 (L) x 1847 (W) x 1821 (H)
 Total size including frame and roof (mm):4159 (L) x 2434 (W)
 Roof type:
Split flat roof, observatory roof rolling over
the warm room roof
 Exterior Cladding:HardiePlank – “Rich Espresso”
 Interior Wall Lining:Marine ply, painted
 Roof Covering:One-piece EPDM rubber membrane
 Roof Pitch:1 degree
 Additional Features:



LED strip lighting built into walls/ceiling
UC4-treated redwood frame
Wood-staved worktop desk
Smart radiator in warm room
UPVC door and window with three openers
Location:Berkshire, UK
Completed:June 2025
Approximate Project Cost*:£14,498

* Approximate project cost does not include VAT, haulage, groundworks, telescope or pier, and represents what a similar project might cost if completed now, including any improvements to our base specification.

Neil Phillipson and his team at Outsideology/Knotonlywood have built me a very impressive bespoke observatory for my stargazing activities. The level of professionalism and efficiency in the build was outstanding and I recommend this company for anyone looking a high class solution.

Chris POULTER