Building Control Compliance Checker for Juliet Balconies

5 min read
Building Control Compliance Checker for Juliet Balconies

Juliet balconies (also known as French balconies) have become a defining feature of contemporary residential design. When executed correctly, a glass Juliet balcony enhances daylight, maximises views, and adds architectural value without increasing a building’s footprint. But from a compliance perspective, Juliet balconies are not purely decorative. They are classified as protective barriers, which means they must meet strict requirements under UK Building Regulations, particularly Approved Document Part K (Protection from Falling).

In this article, we’ve created Building Control Compliance Checker, walking you step by step through the critical installation checks - height, fixings, and drainage - Building Control officers expect to see. Whether you’re a trade installer, architect, or high-end DIYer, this tool helps ensure your glass balustrade Juliet balcony is safe, compliant, and built to last.

Key takeaways - Juliet balcony compliance at a glance

  • Minimum height is 1100mm from finished floor level (Part K)
  • Toughened laminated glass is the preferred choice for safety
  • Glass balustrade fixings must connect to structural elements
  • Wide openings may require thicker glass or additional supports
  • Drainage and water management are part of good compliance
  • Accurate documentation helps avoid Building Control delays

A Practical Step-by-Step Guide to UK Part K Compliance for Juliet Balconies

What is a Juliet balcony under UK building regulations?

A Juliet balcony is a guarding system fixed across a full-height opening - typically sliding or French doors - where there is no external platform to stand on.

Under Part K, a Juliet balcony is treated as a balustrade or guarding, not a balcony. This distinction is critical: the system’s primary role is fall prevention, not access or load-bearing for occupancy.

For glass balustrades, this means:

  • The glass must resist impact loads
  • The fixing method must be structurally sound
  • The finished height must meet minimum guarding requirements

Step-by-step building control compliance checker

Height compliance - Does your Juliet balcony meet Part K?

Minimum height is the first thing Building Control will check. Under Approved Document Part K, guarding must be at least 1100mm high when measured from the internal finished floor level

This measurement includes:
  • Any finished flooring (tiles, timber, carpet)
  • Thresholds or upstands at the door opening

Common compliance pitfall

Many installations fail because the height is measured from structural slab level, not the finished floor. A 20–30mm discrepancy can be enough to trigger a Building Control rejection.

Glass balustrade considerations

For a glass Juliet balcony, height is measured to:

  • The top edge of the glass, or
  • The top of a handrail or capping, if fitted

If you are designing a frameless glass balustrade Juliet balcony, ensure the glass specification allows the full 1100mm without compromising structural performance.

Glass specification – Is the glass suitable for guarding?

Glass used in Juliet balconies must comply with BS EN 12150 / BS EN 14449 and be suitable for use as protective guarding.

Building control expectations
  • Toughened laminated safety glass is strongly recommended
  • Lamination ensures that if the glass breaks, it remains in place
  • Thickness is typically 17.5mm to 21.5mm, depending on span and fixing method

For trade installers, providing glass certification or manufacturer’s data sheets can significantly smooth the Building Control approval process.

Fixings - Are your glass balustrade fixings compliant?

Fixings are one of the most scrutinised aspects of a glass balustrade Juliet balcony installation.

Approved fixing methods

Common compliant systems include:

  • Base-fixed aluminium channels
  • Side-mounted standoff fixings
  • Structural steel angle with clamped glass
Key fixing requirements
  • Fixings must be anchored into a structural element (concrete slab, steel frame, or load-bearing masonry)
  • Plug-and-screw fixings into brick slips or insulation zones are not acceptable
  • Fixing centres must match the system’s structural calculations
  • Load considerations

Under Part K and associated standards:

  • Guarding must resist a horizontal line load
  • Point loads may apply depending on location

For trade professionals, this is where manufacturer load testing and structural calculations add credibility and reduce approval delays.

Opening width and glass span – Does the design push the limits?

Juliet balconies are often installed across wide openings, sometimes 2.5m or more.

Compliance check
  • Large spans may require thicker glass
  • Additional fixings or intermediate supports may be needed
  • Deflection limits must be respected to prevent glass movement under load

A minimalist aesthetic should never compromise structural performance. Building Control officers will often request confirmation that glass balustrades spanning wide openings have been assessed correctly.

Drainage and water management - Often overlooked, always important

While Juliet balconies do not have a standing platform, water management still matters.

Why drainage is relevant
  • Rainwater can track along base channels
  • Poor detailing can cause water ingress at door thresholds
  • Standing water can accelerate corrosion of fixings
Best practice
  • Use drained and ventilated base channels
  • Ensure a slight fall away from the building façade
  • Seal interfaces carefully without trapping moisture

Good drainage detailing demonstrates professional competence and reduces long-term maintenance issues, which is something Building Control increasingly values.

External vs internal fixing – Does it affect compliance?

Juliet balconies can be:

  • Face-fixed externally, or
  • Reveal-fixed within the opening

Both approaches can comply with Juliet balcony regulations, provided:

  • The finished guarding height is correct
  • Fixings are structural
  • Glass performance is suitable

Reveal-fixed systems often appeal to high-end DIYers due to cleaner lines, but tolerances must be exact to avoid compliance issues.

Documentation - Can you prove compliance?

Even a perfectly installed glass Juliet balcony can fail inspection if documentation is missing.

What building control may request
  • Glass specifications
  • Fixing details or system drawings
  • Installation instructions
  • Structural calculations (where applicable)

Providing this information upfront positions you as a knowledgeable professional and speeds up sign-off.

Why a compliance-first approach adds value

For trade professionals, mastering Juliet balcony regulations reduces callbacks, protects your reputation, and builds trust with Building Control officers.

For high-end DIYers, understanding compliance ensures your glass balustrade Juliet balcony is not only visually striking but also safe, insurable, and future-proof.

By treating Part K not as a hurdle but as a design framework, you create Juliet balconies that perform as beautifully as they look.

Want more practical compliance tools?

Bookmark this guide and check back regularly. We publish in-depth resources on glass balustrades, fixing systems, and UK building regulations designed to support real-world installations, not just theory.

If you’re looking for a compliant Juliet balcony and glass balustrade supplier, get in touch with Origin Architectural.