How do you verify vertical extensions competency in Qardho?

Vertical extensions competency risks in Qardho come down to one question: can the builder show, on paper and on a site you can visit, that they have carried new loads on an existing structure? The extension rests on walls and footings someone else built, often without drawings, so the first job is verifying the structure below, not the storey above. Ask for evidence before you ask for a price.

What makes a vertical extension different from a new house?

A new build starts from ground the engineer can inspect and design for. An extension starts from walls, footings and a slab whose condition and capacity may be unknown, and it adds load to all of them. The new columns, ring beam and slab must connect into the old masonry in a way that ties the two together. Sun, salt air and rain can age concrete and mortar, and an existing wall can look sound while its mortar has softened; ask the engineer to confirm the condition of your own walls rather than assume it. A builder who has only poured new slabs on open plots has not met this problem. Evidence of the right experience looks like strengthening details, foundation widenings, or a buttress drawn and built, plus records of what was found below ground before the work started.

How do you check unverified capability without insulting anyone?

Ask for documents, not opinions. Request the structural design and calculations for the extension, signed by the engineer who produced them, and ask which office holds the building permit file. Request concrete cube test results or other strength records for the existing structure, or agree a plan to test it if none exist. Ask for one completed vertical extension the team built and the name of the client, then walk it: look at the junction between old wall and new beam, the roof line, and any cracking. Ask two previous clients what went wrong and how it was fixed. A firm that has done this work will have the papers and the address. One that has not will offer assurances instead. Nothing about this process accuses anyone; it simply applies the same test to every bidder.

What should the contract and supervision cover?

Before work starts, agree in writing who inspects the existing structure, what testing is required, and who signs off each stage. Set hold points: foundation or footing strengthening, column starters, ring beam, slab. At each one, work stops until the engineer inspects it. Confirm with the municipal engineer's office what permits or approvals a vertical extension needs in Qardho and what drawings must be submitted, and check what your contract says about payment against completed and inspected stages. Keep a site diary with dates, pour volumes and any changes. If the builder cannot name an engineer for the structural design, treat that as the first gap to close, not a detail to settle later.

What to do next

Write a one-page evidence request and send it to every bidder before you compare prices. Ask for the structural design and calculations, test records or a testing plan, two referee contacts, and one address you can visit this week. Give a deadline for the papers. Any bid that arrives without them stays unopened until the documents are complete.