SFS for Main Contractors

Main contractors do not buy steel framing. They buy the absence of a problem in the master programme. The package that wins is the one that turns up when it said it would, sequences around the trades either side of it, and hands over evidence that satisfies the building control route without three rounds of chasing. Everything below is about that, not about studs.

By Boyan Stanilov, Managing Director, BAS Frames · Last reviewed October 2026

Logistics on sites with nowhere to put anything

Most of our work is inner London or town centre, where the constraint is rarely the frame. At Hathaway House in W9, a fourteen-storey mixed-use tower plus a four-storey office for HG Construction, there was no site storage at all. Material arrived just-in-time onto canteen decks and was installed from there.

At South Plaza in Bristol for Dako Construction, crane lifts were taken at weekends so the scheme avoided the cost of weekday street closures. At Block B, Grays Place in Slough for 4square there was no crane at all — a telehandler only — across five storeys with a steel pitched roof and bespoke dormers.

None of that is a steel decision. It is a sequencing decision made before the first delivery.

Working around other trades and live buildings

Dry systems install in parallel with mechanical and electrical first fix, which is the main programme argument for SFS and drylining over wet trades. We sequence framing, boarding and firestopping around services so the wall and ceiling lines close cleanly rather than being reopened.

Where the building is occupied, that discipline matters more. At Seething Wells Campus in Kingston for Engie we delivered rooftop extensions to twenty-five student blocks, two weeks each, with a single forklift and students in residence throughout — twenty-four months on one campus without displacing them.

Evidence, not assurances

On any Higher-Risk Building the compartmentation, cavity barriers and firestopping have to be installed as tested systems and evidenced in the golden thread. We hand over structural calculations, fire performance data with test certification per wall type, U-value calculations, acoustic data where applicable, supplier traceability, method statements and a construction control plan.

The point of supplying it as standard is that it removes Gateway 2 as a programme risk for your compliance team, rather than becoming a variation and a delay. See passive fire protection and fire-rated drylining.

Taking over a package mid-scheme

Where a package has been added late, or a previous subcontractor has come off, we can typically mobilise install crews within seven to ten days using pre-ordered standard stock and accelerated design coordination. Urgent mobilisation carries a cost premium — typically 8 to 15 per cent — but on a programme-critical scheme it usually recovers four to six weeks.

At Russell Hill in Purley we inherited a defective ground floor from the preceding works and delivered seven storeys and fifty-four flats for Croydon Council through Selsdon Building Contractor regardless.

Capacity and the delivery record

Fourteen storeys is the tallest infill package we have delivered; eight storeys the tallest standalone structure; 2,000m² the largest single package, installed by four operatives from scissor lifts in six weeks; eighteen metres the tallest studs; 120 minutes the highest fire rating; three weeks the fastest full package. Four clients have placed a second scheme with us.

Why BAS Frames as a subcontractor

One team across design, supply and install, directly employed crews, accreditation in place before you ask, and a documented handover. Send drawings or a tender pack and we will return a fixed, itemised scope with programme assumptions stated.

Related: All sectors | SFS package | Commercial drylining | What is in a package

Packages delivered for main contractors

• Fulham Gas Depot SW6 — for Erith. SFS infill to 120 minutes with manufacturer-verified Promat encasement.
• Hathaway House W9 — for HG Construction. Fourteen storeys, just-in-time to canteen decks, no site storage.
• Seething Wells, Kingston — for Engie. Twenty-five blocks at two weeks each, students in residence.
• Lea Field Way, Bolton — for Conamar Building Services. Eighteen-metre studs installed from MEWPs.
• Russell Hill, Purley — for Selsdon Building Contractor. Seven storeys, fifty-four flats, defective ground floor inherited.

See all completed projects

Frequently asked questions

What accreditations do you hold?

SMAS Worksafe under SSIP and CHAS Accredited Contractor. BAS Constructions Ltd is registered in England and Wales, company number 10504807. Product-specific installer certification for fire systems is confirmed per system at tender stage.

Do you take design responsibility?

We provide structural design and calculations for the frame as part of the package, coordinated with your architect and structural engineer. Where design responsibility sits on a particular scheme depends on the procurement route, and we set that out explicitly in the quotation rather than leaving it implied.

How quickly can you mobilise on a live site?

Standard mobilisation is two to three weeks from order. For programme recovery or a late package we can usually mobilise install crews within seven to ten days using pre-ordered standard stock, at a typical premium of 8 to 15 per cent.

Can you work on an occupied or phased site?

Yes. At Seething Wells we worked across twenty-five blocks over twenty-four months with students in residence, and at Albany Court and Cross Keys we built above occupied flats. Sequencing, delivery windows and access are agreed with the site team before mobilisation.

What documentation do you hand over?

Structural calculations sealed by a chartered structural engineer, fire performance data with test certification for every wall type, U-value calculations, acoustic test data where applicable, supplier traceability, installation method statements and a construction control plan.

Related: build-to-rent and student accommodation for the two scheme types we see most. All our services.