Installing a Reliable Sewage Solution for Your Garden Building

Mariusz Mika
Jun 29
3 min read

Updated: Jul 18

If you're planning to add a toilet, shower, or kitchen sink to your garden building, a proper sewage and wastewater solution is essential. At MM Gardens Services, we help you plan and install a reliable, compliant system tailored to your site conditions.

Main Options for Wastewater Disposal

When it comes to wastewater disposal, there are several options available:

Connection to the Mains Sewer

This is the most common and long-term solution.

It requires trenching and piping to your existing household sewer line.

Usually involves a 1:40 fall (slope) for proper gravity drainage.

May require approval from your local water authority for connection.

Macerator Pump System

Ideal when the garden room is far from the house or downhill from the main drain.

A compact pump grinds waste and pumps it through small pipes to the main system.

Can handle toilets, showers, and sinks effectively.

Soakaway or Drainage Field (for greywater only)

Suitable for sink or shower water when a full sewage connection isn’t required.

Must be installed with care to meet building and environmental regulations.

Not suitable for toilet waste, so careful planning is essential.

Septic Tank or Small Treatment Plant

This is recommended for off-grid or rural sites without access to the mains sewer.

Requires proper installation, an emptying schedule, and compliance with regulations.

🛠️ What’s Involved in the Installation?

The installation process involves several key steps:

Trenching and laying pipes to the required depth.
Calculating the fall for gravity-fed systems.
Installing inspection chambers or rodding points for maintenance.
Providing water supply and venting for toilet systems.
Implementing insulation and frost protection for outdoor runs.
Ensuring compliance with Building Regulations Part H.

These steps are crucial to creating a reliable wastewater system that functions effectively and meets all regulatory requirements.

💬 Need Help or Advice?

We provide full consultation, design, and installation of plumbing and sewage systems for summer houses. Whether it's a simple hand basin or a fully functional garden bathroom, we make sure it’s done right — and up to code.

📞 Contact us for a free site survey or quote.

Plumbing & Sewage – FAQ for Summer Houses

❓ Can I install a toilet or shower in my summer house?

Yes, you can! Many of our clients include a toilet, shower, or even a small kitchen area. This requires proper plumbing, drainage, and possibly a connection to the main sewage system.

❓ Do I need to connect my summer house to the main sewer?

Only if you’re installing wastewater facilities like a toilet, shower, or kitchen sink. Otherwise, a water connection alone may be enough, like for a cold water tap or outdoor use.

❓ What if my summer house is far from the main house or downhill?

No problem! We can install a sewage pumping station, which safely transports wastewater uphill to your existing drains. This is a common solution for garden buildings located at a lower level.

❓ Will I need planning permission for a sewage connection?

Not usually, but your project will need to comply with UK Building Regulations. We’ll advise you on what’s required and can handle applications if needed.

❓ Can I use a composting toilet or off-grid solution instead?

Yes! For remote or eco-friendly installations, we can discuss alternatives such as:

Composting toilets
Greywater systems
Standalone septic tanks or treatment plants

❓ How do you protect pipes from freezing in winter?

We use insulated pipes and ensure all underground plumbing is installed below the frost line. We also advise on frost-proof taps, heaters, or shutoff valves if needed.

📞Still have questions?Get in touch for a free consultation — we’ll explain your options and design a system that works for your garden, budget, and lifestyle.