Having a number of housing programmes spread across multiple different agencies has led to duplication, the splitting of key roles, fragmented decision-making and limited coordination between agencies, Twyford said.
"Kāinga Ora is a new approach. It's a one-stop-shop with a job description to build modern homes and vibrant communities."
The new entity means that HNZ – which was established in 2001 – will be no more.
Although the KiwiBuild programme will still exist, the KiwiBuild Unit – which is responsible for delivering KiwiBuild houses – will now come under Kāinga Ora.
National opposed the bill in the House.
Tamaki MP Simon O'Connor said the bill is an admission of the Government's failure.
"It's a glaring, bold statement of the Government's failure, particularly around KiwiBuild."
Earlier this month, the Government unveiled its KiwiBuild reset – announcing the 100,000 houses target over 10 years would be scrapped.
"This is poor legislation," O'Connor said.
"It's poorly thought-out, and I'll elaborate a bit on that later as to why."
Kāinga Ora will be established through two separate pieces of legislation.
The Bill introduced today will bring together the three agencies. A second Bill later this year will give Homes and Communities its enabling development powers.