Mae deall yr angen am dai ychwanegol yn broses gymhleth a hynod dechnegol, a defnyddir gwahanol ddulliau asesu mewn gwahanol rannau o’r DU ar hyn o bryd. Dros y misoedd diwethaf, mae swyddogion Llywodraeth Cymru - gan gynnwys ystadegwyr o Wasanaeth Ystadegol y Llywodraeth - wedi mynd ati, ar fy nghais i, i gynnal adolygiad o’r trefniadau cyfredol. Rydym wedi cydweithio’n agos ag ymarferwyr profiadol o awdurdodau lleol yng Nghymru a Chymdeithas Llywodraeth Leol Cymru. Rydym hefyd wedi bod yn casglu gwybodaeth am y dulliau a ddefnyddir gan lywodraethau eraill yn y DU i bennu’r angen am dai yn y dyfodol.
Understanding the need for additional housing is a complex and highly technical exercise, and different assessment mechanisms are currently in use in different parts of the UK. Welsh Government officials - including statisticians from the Government Statistical Service - have, at my request, conducted a review of current arrangements over recent months.  We have worked closely with experienced practitioners from Welsh local authorities and the Welsh Local Government Association (WLGA).  We have also gathered information about the approaches used to determine future housing need by the other UK Governments.