IRONBRIDGEFACADES for calderhousing trust

Kestrel House gets a new face. Everyone stays home.

Our proposal to reclad all 22 floors of Kestrel House, replace 1,104 windows and glaze 84 balconies into winter gardens while 426 residents keep living there. Drawn as one set, sheet by sheet, for the four people who sign it.

ClientCalder Housing Trust
Dalia, Owen, Nkechi, Tomasz

Drawing setIBF-2614, rev C
Sent 30 Oct 2026

Price held to31 January 2027
Fixed, itemized

Total as drawn$24,000,000

Sheet 02

You gave us three lines to build to.

They come from Calder's tender brief of June 2026. Every sheet after this one answers at least one of them, and you can jump straight to the answer.

No resident should have to leave their home for this work.

Tender brief, section 1.2

03 Elevation 06 Nkechi

Heating bills need to come down before the 2030 rent review.

Tender brief, section 1.4

04 Wall 07 Program

A facade we never have to explain to a fire officer.

Tender brief, section 3.1

04 Wall 06 Owen

1974Built, precast concrete panels

22Floors, ground plus 21 of homes

168Homes, eight on every floor

426Residents, from four months to 93 years old

1,232Panels on the four faces

31%Cracked or spalling in your 2025 survey

Kestrel House facade retrofitSheet 02 of 09The briefRev C

Drag the platform down Kestrel House.

The work starts at the roof and comes down one floor every four weeks. Stop at any floor to see its four weeks day by day, then pick a home to find its window day.

Platform position, roof to ground

Roof, Jul 2027Ground, May 2029

1974 panelCeramic rainscreenFloor in progressPlatform

Floor 14

8 homes, 19 residents

Month 9of 26 on site

Pick a home on this floor

MonTueWedThuFri

LoudSome noiseQuietWindow daySign-off walkThe color is how the day sounds from inside a home on this floor. Weekends are always quiet.

56of 168 homes finished

142residents in finished homes

0residents moved out

Four loud days per home, booked a month ahead and printed on a card through every door. The platform never works outside a home before 08:30 or after 16:00, and never on a weekend.

Kestrel House facade retrofitSheet 03 of 09South elevationScale 1:200Rev C

What changes inside the wall.

One slice through the wall at a floor line, drawn to scale. Switch between the wall your residents have now and the one they'll have in 2029, then tap a layer to see what it does.

0.18U-value, W/m²K

18.6°CInside face of the wall on a January night

89%Less heat through the wall than today

Kestrel House facade retrofitSheet 04 of 09Wall section at floor lineScale 1:5Rev C

Build the version you'd sign.

Access, repairs and fire stopping are the same in every version. Everything else is a choice, and each line tells you what you'd give up.

We'd build the ceramic rainscreen, triple glazing and winter gardens, with everyone staying home, at $24,000,000. It's the only version that meets all three lines of your brief. The cassettes would save three days a floor and cost $1,780,000 more for a building nobody could tell apart from the street. Moving residents out saves seven months and breaks the first line.

Fixed in every version

The work that has to happen whatever you choose. $6,540,000.

Kestrel House facade retrofitSheet 05 of 09Schedule of pricesRev C

Four people sign this. Each gets a straight answer.

One question from each of you, taken from the clarification meetings in September, answered here so nobody has to wait for a call.

DaliaChief Executive

Dalia, will this still look like the right call in 2029?

Your 2025 options appraisal priced a rebuild at $410,000 a home and six years of moves. This keeps every resident at home for $142,857 a home and finishes in May 2029, a year ahead of the rent review.

The board case comes down to the four rows below. They move with the pricing on sheet 05, so the version you pick is the version you defend.

Retrofit with IronbridgeRebuild, from your appraisal

Cost per home$142,857$410,000

Embodied carbon1,900 t14,600 t

Residents who move out0426

Years from signature2.56

OwenDirector of Assets

Owen, will it pass every fire check and last forty years?

Every layer outside the concrete is non-combustible and rated A1, and the full system has been fire tested at full scale as one build-up, rails and fixings included. Cavity barriers close the gap at every floor and around every window.

Design life is 40 years. The ceramic needs a wash every five, and the facade carries a 12-year insurance-backed warranty that transfers if you ever dispose of the block.

Heat lost through walls, windows and balconies falls 71 percent with the version on sheet 05.

The full specification

Facade: Glazed ceramic rainscreen, 20 mm, on aluminum rails
Insulation: Mineral wool, 160 mm, A1
Wall U-value: 0.18 W/m²K, down from 1.62
Cavity barriers: At every floor and every opening, each one photographed before it's covered
Fixings: Stainless brackets into the inner leaf, pull-tested on every floor
Windows: Triple glazed aluminum, tilt and turn
Warranty: 12 years, insurance-backed, transferable
Upkeep: Wash every five years from the roof cradle we leave in place

NkechiResident Liaison lead

Nkechi, what do I tell the residents on floor 9?

That they stay home, that the loud work outside any one home lasts four days, and that their window day is booked a month ahead with two named fitters. These are the questions from your last two residents' meetings, answered so you can read them out as written.

Do I have to move out?

No. Nobody moves. If you'd rather be out on your window day, the community room on the ground floor is open from 09:00 with tea, wifi and space for the kids.

How long will workers be outside my window?

About four weeks for your floor. Four of those days are loud, and they're printed on a card that comes through your door a month before.

Will anyone come inside my home?

Once, on your window day, for about six hours. Two fitters, the same two for your whole floor, with dust sheets and a vacuum.

What happens to my balcony?

We clear it with you a week before. Plants, bikes and satellite dishes go into free storage and come back to a balcony you can use all year.

Will my heating bill go down?

It should. Our model says about $820 a year for an average home, starting the winter after your floor is done.

Who do I call if something's wrong?

Kerry-Ann, our resident liaison officer, in the site office by the east door, Monday to Friday 08:00 to 17:00. Out of hours, a phone line answered by a person, every night.

TomaszFinance Director

Tomasz, what's the most this costs, and when does it go out?

The price is fixed for the scope you pick, $24,000,000 as drawn. We bill monthly for floors finished and signed off, and you hold back 3 percent until the defects year ends. The one thing that can move it is the concrete repair rate, which is on sheet 08 with a cap.

Quarterly payments. The red bar is the retention, released when the defects year ends.

Payment terms30 days from each monthly valuation
Retention3 percent, $720,000, held until the defects year ends
Your own contingencyWe'd suggest the Trust holds 5 percent, $1,200,000, outside this contract

Kestrel House facade retrofitSheet 06 of 09SignersRev C

Twenty-six months on site, then a year of aftercare.

Dates come from the same schedule as the platform on sheet 03, with the site shut each year from 20 December to 2 January.

Before we're on siteWork on the outside of the buildingHomes handed back

Kestrel House facade retrofitSheet 07 of 09ProgramRev C

The terms, in plain words.

The price is fixed for the scope you choose on sheet 05, and it holds until 31 January 2027.
You pay monthly for finished floors within 30 days. Three percent is held back until the defects year ends.
If we finish late for reasons that are ours, we pay you $18,000 a week, up to 10 percent of the price.
The facade carries a 12-year insurance-backed warranty. In the first year we fix any defect within ten working days.
Any resident can stop loud work outside their home for medical or care reasons. It's built into the program and costs you nothing.
Either of us can pause the job at the end of a floor with 20 working days' notice.

Four things we can't price yet.

The concrete under the panels

We've cored three floors. If repairs on the other nineteen run more than 15 percent over our allowance, the extra is billed at the rates in our schedule, capped at $480,000.

Asbestos in the balcony soffits

Your 2019 survey found it on two floors and we've priced removal there. If it turns up on more, it's a fixed $9,400 a balcony.

Planning consent for winter gardens

Officers were positive at the pre-application meeting. If consent is refused we switch to repair and new rails, and the price drops $1,370,000.

Power for heat-recovery units

Only if you choose them. The building's supply may need an upgrade, and the power company quotes in January.

Kestrel House facade retrofitSheet 08 of 09Terms and open questionsRev C

Sign by 15 December and residents meet us in January.

The letter of intent opens the site office, books the first residents' drop-in for 16 January, and lets us core the other nineteen floors before the price is final. Each of you signs for your own part.