The Overlooked Role of Wall Ties in Low‑Carbon Housing Design

With the UK construction sector preparing for the Future Homes Standard in 2026, the focus on delivering thermally efficient, fabric-first homes has never been stronger. Wider cavities, improved U-values and more stringent Part L requirements demand greater attention to the components that sit within the building envelope. One of the most critical, but often overlooked, elements is the humble wall tie.

Correct specification and installation of wall ties is essential to achieving compliant thermal performance, structural stability, moisture control and acoustic separation. It’s why Ancon wall ties are already engineered with the performance needed for the Future Homes Standard and the next generation of low-carbon housing.

Wider cavities and structural considerations

The drive for improved fabric performance has led to wider masonry cavities across UK housing. As insulation thickness increases, the choice of wall tie becomes more complex design consideration, particularly in relation to length, embedment and compliance with PD 6697:2019.

Typical Ancon cavity wall ties are designed with a 62.5mm embedment depth, ensuring consistent structural performance and accommodating real-world site tolerance. For example, the Ancon Staifix HRT4 300mm tie is designed specifically for cavity widths of 151–175mm, aligning with the insulation depths required to meet upcoming Future Homes Standard U-values.

Equally important is their structural capacity. PD 6697:2019 sets out tie types (1–4) based on structural application. For domestic buildings up to 10 metres in height, Type 4 ties such as the Ancon Staifix HRT4 are fully compliant for light-duty applications. When used in party walls, ties must also meet Part E acoustic requirements, which is something Ancon ties have been rigorously tested and approved for, with different ties offering varying acoustic capacities to suit specific wall constructions.

Minimising thermal bridging

In wider cavities, the risk of thermal bridging through metal components increases. Poor tie selection, or incorrect installation, can undermine the entire thermal strategy of a dwelling.

Material choice is critical. Stainless steel offers low conductivity, but for projects where thermal performance is paramount, the Ancon Teplo-BF basalt fibre tie delivers exceptional results with a conductivity of just 0.7 W/mK. This innovative material is excluded from U-value calculations under BS EN ISO 6946, making it ideal for low-energy and fabric-first designs, while other Ancon Teplo tie variants are available for a range of applications.

Good installation practice is equally important. Insulation should not be compressed or displaced by wall ties, and ties must be correctly positioned to maintain the integrity of the thermal layer. Leviat’s technical team supports designers and contractors to ensure optimal tie selection and detailing.

Moisture and durability

Wall ties also play a key role in moisture management within the cavity. In acknowledgment of this established requirement, Ancon ties, including the Ancon Staifix HRT4, feature multi-drip details that prevent moisture from crossing the cavity and reaching internal structure.

Stainless steel construction ensures long-term corrosion resistance, critical for wider cavities where exposure is increased. Installation must be carefully controlled, with ties installed horizontal or with a slight fall toward the outer leaf to direct moisture away from the building.

Getting installation right

Despite their apparent simplicity, wall tie installation errors are not uncommon on site. Common issues include incorrect tie length, bending ties on site, installing ties with mortar on them, or installing them with misaligned drips.

PD 6697:2019 recommends a minimum of 2.5 ties per m², with tighter spacing near openings and unbonded edges, and where sites are subject to greater wind exposure. Leviat’s clear guidance and installer support help avoid these common pitfalls and ensure compliant, durable construction.

Leave it to Leviat

The Future Homes Standard will mean stricter thermal performance requirements and so wall ties must no longer be treated as an afterthought. Structural integrity, thermal efficiency, moisture management and acoustic compliance all depend on selecting the correct tie from the outset and following the correct installation guidance on site.

Ancon wall ties are engineered to meet and exceed these requirements. With proven performance, independent approvals and expert technical support, Leviat is helping the industry build homes that are safe, efficient and fully future-ready.

To learn more visit: https://www.ancon.co.uk/products/wall-ties-restraint-fixings/cavity-wall-ties

Alternatively contact us on tech.ancon.uk@leviat.com or call +44 (0) 114 275 5224