diff --git a/src/builder/CMakeLists.txt b/src/builder/CMakeLists.txt
index 1d24227..9160968 100644
--- a/src/builder/CMakeLists.txt
+++ b/src/builder/CMakeLists.txt
@@ -11,6 +11,7 @@ set(SRCS
 	b-logproxy.c
 	b-refproxy.c
 	b-load.c
+	b-metrics.c
 	../common/c-utils.c
 )
 
diff --git a/src/builder/b-comms.c b/src/builder/b-comms.c
index 80116b6..8f955e4 100644
--- a/src/builder/b-comms.c
+++ b/src/builder/b-comms.c
@@ -482,6 +482,8 @@ saib_sul_load_report_cb(struct lws_sorted_usec_list *sul)
         */
        lws_strncpy(lr->builder_name, builder.host, sizeof(lr->builder_name));
        lr->core_count = saib_get_cpu_count();
+       lr->free_ram_kib = saib_get_free_ram_kib();
+       lr->free_disk_kib = saib_get_free_disk_kib(builder.home);
 
        int system_load = saib_get_system_cpu(&builder);
 
diff --git a/src/builder/b-metrics.c b/src/builder/b-metrics.c
new file mode 100644
index 0000000..b577f73
--- /dev/null
+++ b/src/builder/b-metrics.c
@@ -0,0 +1,100 @@
+/*
+ * sai-builder-metrics
+ *
+ * Copyright (C) 2019 - 2021 Andy Green <andy@warmcat.com>
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation:
+ *  version 2.1 of the License.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ *  MA  02110-1301  USA
+ */
+
+#include <libwebsockets.h>
+#include "b-private.h"
+
+#if defined(__linux__)
+#include <sys/statvfs.h>
+#elif defined(__APPLE__)
+#include <sys/sysctl.h>
+#include <mach/mach.h>
+#include <mach/vm_statistics.h>
+#endif
+
+unsigned int
+saib_get_free_ram_kib(void)
+{
+#if defined(__linux__)
+	char buf[256];
+	FILE *f;
+	unsigned int free_kib = 0;
+
+	f = fopen("/proc/meminfo", "r");
+	if (!f)
+		return 0;
+
+	while (fgets(buf, sizeof(buf), f)) {
+		if (sscanf(buf, "MemAvailable: %u kB", &free_kib) == 1)
+			break;
+	}
+
+	fclose(f);
+	return free_kib;
+#elif defined(__APPLE__)
+	int mib[2];
+	size_t len;
+	uint64_t total_mem;
+	vm_size_t page_size;
+	mach_msg_type_number_t count;
+	vm_statistics64_data_t vm_stats;
+
+	mib[0] = CTL_HW;
+	mib[1] = HW_MEMSIZE;
+	len = sizeof(total_mem);
+	sysctl(mib, 2, &total_mem, &len, NULL, 0);
+
+	count = HOST_VM_INFO64_COUNT;
+	if (host_statistics64(mach_host_self(), HOST_VM_INFO64, (host_info64_t)&vm_stats, &count) != KERN_SUCCESS)
+		return 0;
+
+	return (unsigned int)((uint64_t)vm_stats.free_count * vm_stats.pagesize / 1024);
+#elif defined(_WIN32)
+	MEMORYSTATUSEX statex;
+	statex.dwLength = sizeof(statex);
+	GlobalMemoryStatusEx(&statex);
+	return (unsigned int)(statex.ullAvailPhys / 1024);
+#else
+	return 0;
+#endif
+}
+
+unsigned int
+saib_get_free_disk_kib(const char *path)
+{
+#if defined(__linux__) || defined(__APPLE__)
+	struct statvfs s;
+
+	if (statvfs(path, &s))
+		return 0;
+
+	return (unsigned int)((uint64_t)s.f_bavail * s.f_frsize / 1024);
+#elif defined(_WIN32)
+	ULARGE_INTEGER free_bytes;
+
+	if (!GetDiskFreeSpaceExA(path, &free_bytes, NULL, NULL))
+		return 0;
+
+	return (unsigned int)(free_bytes.QuadPart / 1024);
+#else
+	return 0;
+#endif
+}
diff --git a/src/builder/b-private.h b/src/builder/b-private.h
index 4f1c75b..7146d14 100644
--- a/src/builder/b-private.h
+++ b/src/builder/b-private.h
@@ -229,3 +229,8 @@ saib_get_system_cpu(struct sai_builder *b);
 
 int saib_get_cpu_count(void);
 
+unsigned int
+saib_get_free_ram_kib(void);
+
+unsigned int
+saib_get_free_disk_kib(const char *path);
diff --git a/src/common/include/private.h b/src/common/include/private.h
index f821db3..6b017a1 100644
--- a/src/common/include/private.h
+++ b/src/common/include/private.h
@@ -85,6 +85,8 @@ typedef struct sai_load_report {
 	char			builder_name[64];
 	int			core_count;
 	lws_dll2_owner_t	platforms; /* List of sai_platform_load_t */
+	unsigned int		free_ram_kib;
+	unsigned int		free_disk_kib;
 } sai_load_report_t;
 
 /*
diff --git a/src/common/struct-metadata.c b/src/common/struct-metadata.c
index 73dc8ea..7d62719 100644
--- a/src/common/struct-metadata.c
+++ b/src/common/struct-metadata.c
@@ -36,6 +36,8 @@ const lws_struct_map_t lsm_platform_load[] = {
 const lws_struct_map_t lsm_load_report_members[] = {
 	LSM_CARRAY	(sai_load_report_t, builder_name, "builder_name"),
 	LSM_SIGNED	(sai_load_report_t, core_count,	"core_count"),
+	LSM_UNSIGNED	(sai_load_report_t, free_ram_kib, "free_ram_kib"),
+	LSM_UNSIGNED	(sai_load_report_t, free_disk_kib, "free_disk_kib"),
 	LSM_LIST	(sai_load_report_t, platforms, sai_platform_load_t, list,
 			 NULL, lsm_platform_load, "platforms"),
 };