Here’s 1 idea and 3 details to raise your EngQ.

ONE IDEA: Use light-weight materials so you can reuse the existing foundations

SOM were appointed to replace a 1970’s library

They could have rebuilt it in reinforced concrete

But full demolition makes so much waste

So instead they tried to reuse the existing foundations

Which means the new building couldn’t weigh more than the old

So SOM used a timber frame (the lightest option) and kept the basement

This saved 65% of material waste and sequestered 1 700 tonnes of carbon

SOM used a light-weight structure so they could reuse the existing foundations

Maybe an idea for your project ?

THREE DETAILS: Columns, fire protection and beams

(1) It had to stay standing in an earthquake

So they needed ductile columns and bracing

Again they could have used reinforced concrete

But opted for steel framing (lighter)

(2) It had to stay standing in a fire

They could have used intumescent paint (ugly)

They could have used fireboard to cover the structure (different aesthetic)

Instead they used hollow SHS columns filled with concrete (discrete)

(3) It had to have long spans using timber

They could have used timber trusses (very tall)

They could have used glulam beams (very wide)

Instead they split the glulam beams into pairs (less imposing, easier to build)

Maybe a detail for your project ?

There's some sketches (right) with more information.