BillyOh Tessa Tongue and Groove Reverse Apex Summerhouse

FREE delivery in 1 - 2 weeks
from £3,359

BillyOh Petra Tongue and Groove Reverse Apex Summerhouse

FREE delivery in 1 - 2 weeks
from £3,829

BillyOh Holly Tongue and Groove Apex Summerhouse

FREE delivery by FRI. 10 Dec.*
from £3,333

Our BillyOh 20 x 10 summerhouses are the largest summerhouse model we produce and therefore, offer the ultimate luxury in usable garden space. Below, we’ve listed our most popular models to give you an idea of what style suits might suit you best:


BillyOh Holly Tongue and Groove Apex Summerhouse

The Holly Apex Summerhouse is a stylish and contemporary garden building that is perfect for relaxing in your garden all year round. With a strong Tongue & Groove build, the summerhouse is durable and long-lasting, becoming a feature of your garden for years to come. The Holly is complete with wide opening double doors for easy access and stunning long windows, which provide natural light and a view of your garden.


BillyOh Petra Tongue and Groove Reverse Apex Summerhouse

The Petra summerhouse is a great companion during the summer months and provides a cosy relaxing space throughout the rest of the year. The large windows and optional door placement allows you to get as much natural light as possible, great for entertaining.


BillyOh Tessa Tongue and Groove Reverse Apex Summerhouse

The breathtaking long windows, multi-access doors and strong construction make this summerhouse stand out from the crowd and a great addition for any garden!



Our tongue and groove panelling provides a weather-resistance, tight interlocking seal to keep you warm in winter and cool in summer. However, to further insulate your summer house, you could consider:


  • Using a draught excluder.
  • Installing a vapour barrier.
  • Installing floor ad roofing Celotex insulation sheets.
  • Upgrading to double-glazed windows.

This can be especially useful if you plan to use your summerhouse as a home office throughout the year or overnight. For more, read our guide to damp-proofing and insulating a garden building.



All of our BillyOh summerhouses come as pre-cut tongue and groove panels ready for you to assemble. Simply follow the instructions provided with your order and you and a friend (using some basic tools) can have your summerhouse assembled in no time.



With our 20 x 10 summerhouses you’ll have the option to add-on wood stains and even exterior paint colours for you to apply from our high-quality trade selection. You can go for a dark stain for a more traditional look or even earthy and light, neutral colours to maximise on the sense of space in your summerhouse.