What this page does, and what it refuses to do
It costs three contracts. It does not tell you whether they are lawful, because that is a live disagreement between serious scholars and a calculator is not where it gets settled.
Those who approve these structures hold that they are genuine contracts of sale or partnership: the financier takes real ownership, carries the risks that come with it, and profits from a thing rather than from time on a debt. Those who object hold that some implementations reproduce a loan in substance while changing its form — most often pointing at rent benchmarked to an interest index. Both positions are held by people worth listening to, and what is offered in your town may satisfy one and not the other.
So the page shows the cost, plainly, so that the question you take to a scholar is a specific one about a specific contract rather than a general one about a category.
Three contracts, not three brand names
Murabaha is a sale. The financier buys the house and sells it to you at a mark-up they disclose, payable in instalments. The price is fixed at the outset and cannot rise — not if rates move, and not if you fall behind, because a fixed sale price is not a balance that accrues. That certainty is its main advantage and it is usually paid for in the mark-up.
Ijara is a lease. They buy the house and lease it to you, with part of the payment buying ownership over the term. The rent is normally reviewed at intervals, so the total is not knowable at the start — which makes the review clause, not the headline rate, the thing to read.
Diminishing musharakah is a partnership, and it is what most providers in Britain and America actually offer. You and the financier own the property together. You pay rent on their share and buy pieces of it back; as your share grows the rent falls, and so does the monthly payment. This is the structure whose arithmetic differs most visibly from a mortgage — a mortgage keeps the payment level and shifts the split inside it, while this one genuinely falls month by month.
Why the totals differ, and why that is not a bargain
On identical figures, diminishing musharakah comes out cheapest. That is because a return charged on a shrinking share costs less than the same rate on the whole sum for the whole term. It is arithmetic, and a provider prices for it: the rate quoted on a musharakah accounts for exactly this.
Which is why comparing two providers on headline rate alone will mislead you. Compare the total over the term, which is what the table on this page puts side by side.
Four questions worth asking before you sign
Who holds legal title, and who carries the loss if the property burns down. Whether the rate is fixed or reviewed, and if reviewed, against what and how often. What happens on late payment, and whether any charge is kept as profit or given away. And whether the provider has a shariah supervisory board, who sits on it, and whether its ruling on this product is published.
A provider who answers the first three easily and hesitates on the fourth has told you something. And it is worth remembering that avoiding riba creates no obligation to buy a house at all — renting while saving raises none of these questions.