The main frame of the roundhouse would have been made of upright timbers, which were interwoven with coppiced wood - usually hazel, oak, ash or pollarded willow - to make wattle walls. This was then covered with a daub made from clay, soil, straw and animal manure that would weatherproof the house. The roof was constructed from large timbers and densely thatched. All of the domestic life would have occurred within the roundhouse.
KS2 History Timelines- The Iron Age Timeline Posters
A new pair of publications from the Latvian National Culture Centre: a 2017 wall calendar and a planner with photos of authentic replicas of 7th-14th century garb representing all the chiefdoms of Late Iron Age Latvia. This one is Latgallian (not sure of the century). I'm going to try to get some of these for balticsmith.com.
Pembrokeshire. Interior of the re-created Chieftains Hut, an Iron Age Celtic Roundhouse built on the original foundations ,
The replica Iron Age roundhouse - Cornwall. Unique place to stay
Castell Henllys. "The Iron Age Celts' clothes might have looked like the tartan you see in Scotland and Ireland today, with checks and stripes. The Celts used berries and plants to dye the wool different colours."-BBC